Answer:
D) Q/2
Explanation:
The relationship between charge Q, capacitance C and voltage drop V across a capacitor is
[tex]Q=CV[/tex] (1)
In the first part of the problem, we have that the charge stored on the capacitor is Q, when the voltage supplied is V. The capacitance of the parallel-plate capacitor is given by
[tex]C=\frac{\epsilon_0 A}{d}[/tex]
where [tex]\epsilon_0[/tex] is the vacuum permittivity, A is the area of the plates, d is the separation between the plates.
Later, the voltage of the battery is kept constant, V, while the separation between the plates of the capacitor is doubled: [tex]d'=2d[/tex]. The capacitance becomes
[tex]C'=\frac{\epsilon_0 A}{d'}=\frac{\epsilon_0 A}{2d}=\frac{C}{2}[/tex]
And therefore, the new charge stored on the capacitor will be
[tex]Q'=C'V=\frac{C}{2}V=\frac{Q}{2}[/tex]
A monochromatic light passes through a narrow slit and forms a diffraction pattern on a screen behind the slit. As the wavelength of the light decreases, the diffraction patterna)spreads out with all the fringes getting wider.b)remains unchangedc)spreads out with all the fringes getting alternately wider and then narrower.d)becomes dimmere)shrinks with all the fringes getting narrower.
bvcdbcvfdnbgfbjdgfhdgfjghfjhvjbczdfsghdfshjdgfhdftgh
What is the velocity of all electromagnetic waves in a vacuum?
Answer:
[tex]c=3\cdot 10^8 m/s[/tex]
Explanation:
All electromagnetic waves travel in a vacuum at the same speed, regardless of their frequency. The magnitude of their velocity is
[tex]c=3\cdot 10^8 m/s[/tex]
This value is one of the universal constant and it is called speed of light.
According to Einstein's theory of special relativity, the value of c is the same for all inertial frames (it means that we measure always the same value of c in a vacuum, even if we are moving with respect to the light).
However, the speed of the electromagnetic waves decreases as they move through a medium. In particular, their speed decreases according to the equation:
[tex]v=\frac{c}{n}[/tex]
where n is called index of refraction of the medium.
A carnot heat engine receives 600 kj of heat from a source of unknown temperature and rejects 175 kj of it to a sink at 20°c. determine (a) the temperature of the source and (b) the thermal efficiency of the heat engine.
(b) 71%
The thermal efficiency of a Carnot heat engine is given by:
[tex]\eta = \frac{W}{Q_{in}}[/tex]
where
W is the useful work done by the engine
[tex]Q_{in}[/tex] is the heat in input to the machine
In this problem, we have:
[tex]Q_{in}=600 kJ[/tex] is the heat absorbed
[tex]W=600 kJ-175 kJ=425 kJ[/tex] is the work done (175 kJ is the heat released to the sink, therefore the work done is equal to the difference between the heat in input and the heat released)
So, the efficiency is
[tex]\eta = \frac{425 kJ}{600 kJ}=0.71 = 71\%[/tex]
(a) [tex]737^{\circ}C[/tex]
The efficiency of an engine can also be rewritten as
[tex]\eta = 1-\frac{T_C}{T_H}[/tex]
where
[tex]T_C[/tex] is the absolute temperature of the cold sink
[tex]T_H[/tex] is the temperature of the source
In this problem, the temperature of the sink is
[tex]T_C = 20^{\circ}C + 273=293 K[/tex]
So we can re-arrange the equation to find the temperature of the source:
[tex]T_H = \frac{T_C}{1-\eta}=\frac{293 K}{1-0.71}=1010 K\\T_H = 1010 K - 273=737^{\circ}C[/tex]
Final answer:
To address the question, the source temperature is derived using the Carnot efficiency equation, revealing it must be higher than 20°C for the engine to operate. The thermal efficiency is calculated to be 70.83%, representing the work done versus heat absorbed ratio.
Explanation:
A Carnot heat engine's efficiency and the temperatures of its heat reservoirs are interconnected through the principles of thermodynamics. Given that a Carnot heat engine receives 600 kJ of heat from a source and rejects 175 kJ to a sink at 20°C, we can determine both the temperature of the source and the engine's thermal efficiency.
Calculation of the Source Temperature
To find the source temperature, we use the Carnot efficiency formula: Efficiency = 1 - (QC/QH), where QC is the heat rejected to the cold sink, and QH is the heat received from the hot source. First, we calculate the engine's efficiency: Efficiency = 1 - (175kJ/600kJ) = 0.7083.
Because the Carnot efficiency is also given by Efficiency = 1 - (TC/TH), where TC = 293K (equivalent to 20°C), we can rearrange for TH: TH = TC / (1 - Efficiency). After substituting the known values, we find the temperature of the source to be higher than the sink, as expected.
Thermal Efficiency of the Heat Engine
The thermal efficiency of the Carnot engine is calculated to be 70.83%, which means that 70.83% of the heat input from the source is converted to work, while the remainder is rejected to the sink.
The four lines observed in the visible emission spectrum of hydrogen tell us that
a) Only certains energies are allowed for the electron in a hydrogen atomb) There are four electrons in an excited hydrogen atomc) the hydrogen molecules they came from have the formula H₄d) We could observe more lines if we had a stronger prism
The visible emission lines of hydrogen indicate that only certain energies are permissible for its electron. This is due to quantum mechanics, affirming that electrons within atoms exist at distinct energy levels, and emit light of specific wavelengths when transitioning between levels.
Explanation:The four lines in the visible emission spectrum of hydrogen tell us that only certain energies are allowed for the electron in a hydrogen atom. This is related to the principle of quantum mechanics where an electron in an atom can only exist in discrete energy levels.
When the electron jumps from a higher energy level to a lower one, it emits light of a specific wavelength. The lines we see in the hydrogen emission spectrum represent these wavelengths. Hence, these lines don't mean there are four electrons in an excited hydrogen atom, nor that the hydrogen molecules have the formula H₄. Also, using a stronger prism would not lead to the observation of more lines, but would merely spread the existing lines out more.
Learn more about Emission Spectrum here:https://brainly.com/question/27268130
#SPJ3
Suppose an ice hockey puck strikes a hockey stick that lies flat on the ice and is free to move in any direction. Which
quantities are likely to be conserved: angular momentum, linear momentum, or kinetic energy (assuming the puck and stick are
very resilient)?
Answer:
Linear momentum
Explanation:
The most likely conservation candidate is the linear momentum. The law of momentum conservation states that the sum of momenta before and after an (elastic or inelastic) collision will remain constant.
The kinetic energy is another possible, but less likely suspect. It is conserved in elastic collisions (i.e., those with no kinetic energy loss), but we are not told this collision is assumed elastic. In fact the real setup would be nowhere close to an elastic collision, as the stick lies on ice, which hasn't be zambonied for an entire period of rough skating, there's rough surface and the stick's shaft is also slightly stuck to the surface through frost. So when the puck hits the stick, a portion of its kinetic energy is spent to unstick the stick and get it moving. And so, kinetic energy is not conserved.
Angular momentum is not applicable with the puck-stick scenario.
In the described scenario, both angular and linear momentum are likely to be conserved, while kinetic energy may not be due to potential energy conversion during the impact.
Explanation:In this scenario regarding an ice hockey puck hitting a hockey stick on ice, both angular momentum and linear momentum would likely be conserved. The conservation of angular momentum comes into play as the hockey puck changes its direction, and linear momentum is conserved as long as there are no external forces acting on it, as is the case in this scenario. On the other hand, kinetic energy would not necessarily be conserved because some energy might be converted into other forms such as heat or sound during the impact.
Learn more about Conservation of Momentum here:https://brainly.com/question/32309314
#SPJ2
What is the velocity of all electromagnetic waves in a vacuum?
The velocity of electromagnetic waves depends upon their wavelength. Electromagnetic waves do not propagate forward; hence, their velocity is zero. The velocity of electromagnetic waves is nearly equal to 3 × 108 m/s. The velocity of electromagnetic waves depends upon their frequency. The velocity of electromagnetic waves depends upon their amplitude.
Answer:
The velocity of electromagnetic waves is nearly equal to 3 × 108 m/s.
Explanation:
All electromagnetic waves travel at the same speed in a vacuum. The value of their velocity does not depend neither on their frequency, nor on their wavelength.
The magnitude of their velocity is known as speed of light (labelled with c), and it is one of the universal physical constant:
[tex]c=2.998 \cdot 10^8 m/s[/tex]
The velocity of electromagnetic waves changes instead when they travel in a medium (in particular, their speed decreases)
The velocity of all electromagnetic waves in a vacuum is 3 × 10^8 m/s, which is the speed of light and a fundamental physical constant.
Explanation:In a vacuum, all electromagnetic waves travel at the same speed, which is the speed of light, approximately 3 × 10^8 m/s. This is one of the fundamental physical constants and is denoted by the symbol c. Regardless of their wavelength or frequency, electromagnetic waves propagate through space at this constant velocity. Therefore, the velocity of all electromagnetic waves in a vacuum is 3 × 10^8 m/s.
Individual sports are different from team sports in that they require an internal focus and dialogue. Please select the best answer from the choices provided. T F
Answer:
true
Explanation:
It is true that individual sports is different from team sports.
Individual sports depend upon the individual's hard work, focus,determination only he is responsible for his fate.
when we talk about team sports it is about co-ordination , team brilliance individual cannot team sport alone every one have to contribute for the team to succeed.
Individual sports are different from team sports in that they require an internal focus and dialogue. The statement is true.
Individual sports and team sports do have distinct characteristics, and one of the notable differences is the emphasis on internal focus and dialogue in individual sports.
In individual sports, athletes compete on their own without relying on teammates. They have sole responsibility for their performance, decision-making, and strategy execution.
As a result, individual athletes often rely heavily on their internal focus to stay motivated, maintain concentration, and push themselves to perform at their best.
They engage in internal dialogues to manage their thoughts, emotions, and self-motivation throughout the competition. This internal focus and dialogue help them stay focused, make quick decisions, and adapt to changing circumstances.
Know more about Individual sports:
https://brainly.com/question/872862
#SPJ6
Measure the length of the arrow in centimeters using correct significant figures.
l = 3 cm
l = 3.3 cm
l = 3.35 cm
l = 3.351 cm
Based on the very tip of the arrow the best answer would be; 3.3cm
But i could very well be wrong and it may be 3.35, but i would say 3.3 if it just wants to the nearest 10th
Answer:
The significant figures is 3.3 cm.
Explanation:
Significant :
Significant figures of a number are numbers that have significance to contribute to its resolution of measurements.
Centimeter is unit of length.
According to figure,
The significant figures is
[tex]l = 3.3\ cm[/tex]
Hence, The significant figures is 3.3 cm.
A 0.20 kg plastic cart and a 20 kg lead cart can roll without friction on a horizontal surface. Equal forces are used to push both carts forward for a time of 1 , starting from rest. After the force is removed at t = 1s is the momentum of the plastic cart greater than, less than, or equal to the momentum of the lead cart? Explain.
Answer:
The have equal momentum
Explanation:
The change in momentum of each cart is equal to the impulse given to the cart:
[tex]\Delta v = I = F \Delta t[/tex]
where
F is the average force exerted on the cart
[tex]\Delta t[/tex] is the contact time
In this case, the force F applied to both carts is the same, and the contact time is the same for both carts (1 s). Therefore, the change in momentum of the two carts is the same.
However, both carts at the beginning have a momentum of zero (because they start from rest): this means that their final momentum will be equal, since they gain the same amount of momentum [tex]\Delta p[/tex].
Due to the relationship in the momentum equation, (p = mv) and equal forces applied on the two carts, both the plastic and the lead cart will have equal momentum irrespective of their mass differences.
Explanation:The momentum of the plastic cart and the lead cart will be equal. This is because momentum is the product of mass and velocity (p = mv). As equal forces are applied for the same duration, according to Newton's second law of motion, the acceleration a = F/m is equal for both carts. As the smaller plastic cart has less mass, it will have a greater velocity, while the larger lead cart, having more mass, will have a lesser velocity. However, because of the relationship in the momentum equation (p = mv), these different velocities will effectively cancel out the mass differences, resulting in equal momentum for the two carts.
Learn more about Momentum here:https://brainly.com/question/30677308
#SPJ3
A 41 g ball rolls around a 64-cm-diameter L-shaped track at 55 rpm. What is the magnitude of the net force that the track exerts on the ball? Rolling friction can be neglected.
Using Newton's Second Law for Rolling Motion and centripetal force formulas, the magnitude of the net force exerted on a 41 g ball rolling at 55 rpm on a 64-cm-diameter track is calculated to be approximately 0.4307 Newtons.
To find the magnitude of the net force that the track exerts on the ball, we apply Newton's Second Law to Rolling Motion. We begin by converting the rotational speed to angular velocity: 55 rpm (revolutions per minute) is equivalent to 55 × 2π rad/60s ≈ 5.7596 rad/s. The radius (r) of the circular path is half the diameter, hence r = 64 cm / 2 = 32 cm = 0.32 m.
The ball experiences centripetal force due to its circular motion, which is defined as F = m × ω² × r, where m is the mass, ω is the angular velocity, and r is the radius. Plugging in the values, we get F = 0.041 kg × (5.7596 rad/s)² × 0.32 m ≈ 0.4307 N.
Therefore, the magnitude of the net force that the track exerts on the ball, considering rolling friction is neglected, is 0.4307 Newtons.
The net force exerted by the track on the ball is 0.435 N, calculated using the ball's mass, track radius, and angular velocity. This force is derived by finding the centripetal force required for circular motion.
To find the magnitude of the net force that the track exerts on a ball, we first identify the necessary parameters. The mass of the ball is 41 g, which we convert to kg (0.041 kg). The diameter of the track is 64 cm, giving us a radius of 0.32 m. The ball moves with a frequency of 55 rpm, which we convert to angular velocity.
Convert RPM to radians per second:Therefore, the magnitude of the net force that the track exerts on the ball is 0.435 N.
A transformer is a device used to increase or decrease the voltage through induction. Which fundamental force is responsible for this induction?ElectromagneticWeak NuclearStrong NuclearGravitational
The two nuclear forces are not responsible for this property.
Gravitational is far too weak to make a transformer work.
The answer is electromagnetic.
The electromagnetic force is responsible for the induction in a transformer. It's due to the production and interaction of electric and magnetic fields, following Faraday's Law of electromagnetic induction.
Explanation:The fundamental force responsible for the induction in a transformer is the Electromagnetic Force. This is due to the production and interaction of electric and magnetic fields in the transformer. The function of a transformer is primarily based on Faraday's Law of electromagnetic induction which states that a change in magnetic field within a closed loop of wire induces an electromotive force (EMF) in the wire. When you apply alternating current in the primary coil, it creates a constantly changing magnetic field around the secondary coil. This changing magnetic field induces a voltage in the secondary coil, either increasing or decreasing it based on the number of turns in both the coils.
Learn more about Electromagnetic Force here:https://brainly.com/question/10763830
#SPJ6
How are the sun, the moon, and Earth related during a solar eclipse?
A.) Earth is located between the sun and the moon.
B.) The moon is located between the sun and Earth.
C.) The sun is located between the moon and Earth.
D.) Earth and the moon are located on opposite sides of the sun.
B. The moon is located between the Sun and Earth
Answer:
B.
hope this helps!!!!
Which of the following is a measure of the average kinetic energy of the particles in a sample of matter? A. Chemical kinetics B. thermochemistryC. reaction rateD. temperature
Answer:
D. Temperature
Explanation:
The temperature of a substance is directly proportional to the average kinetic energy of the particles in the substance according to the equation (valid for monoatomic gases)
[tex]E_K = \frac{3}{2}kT[/tex]
where
Ek is the average kinetic energy
k is the Boltzmann's constant
T is the temperature
From the equation, we see that the temperarure is directly proportional to the average kinetic energy, so the correct answer is
D. temperature
A light wave travels through space at a speed of 3 x 108 m/s. If the wavelength of some light wave is 2 x10-3 m, what is the frequency of the wave?
6.67 x 10-12 Hz
1.5 x1011 Hz
6 x105 Hz
2 x 10-3 Hz
Here is your answer
b) [tex]\huge 1.5× {10}^{11} Hz [/tex]
REASON :
We know that
Velocity= Frequency× Wavelength
So,
Frequency= Velocity/wavelength
Here,
V= 3× 10^8 m/s
Wavelength= 2×10^-3 m
Hence,
Frequency= 3×10^8/2×10^-3
= 3/2 × 10^11
= 1.5× 10^11 Hz
HOPE IT IS USEFUL
The frequency of a light wave with a given speed of 3 x 10^8 m/s and wavelength of 2 x 10^-3 m can be calculated using the formula: frequency = speed / wavelength. The frequency of this wave is 1.5 x 10^11 Hz.
Explanation:The speed of a wave is related to its frequency and wavelength by the formula: speed = frequency * wavelength. So, to find the frequency of a light wave given its speed and wavelength, we can rearrange that formula to get: frequency = speed / wavelength. Substituting the given values:
frequency = (3 x 108 m/s) / (2 x 10-3 m) = 1.5 x 1011 Hz.
So, the frequency of the light wave is 1.5 x 1011 Hz.
Learn more about Light Wave Frequency here:https://brainly.com/question/31753960
#SPJ3
The air over Earth's surfaces absorbs heat from the materials of Earth. In Section 3 of the experiment, the air over the sand the air over the water because sand water. This difference in temperatures makes the air over the sand the air over the water so it rises. The air above the water takes the place of the air above the sand. This movement of air creates a sea breeze.
Answer:
1.) is warmer than
2.) heats up faster than
3.) less dense than
Explanation:
e2020
Answer:
1. 2:Is warmer than
2. 1:Heats up faster than
3. 1:Less dense than
A piano string sounds a middle A by vibrating primarily at 220 Hz.a)Calculate its period.b)Calculate its angular frequency.c)Calculate the period for a soprano singing a "high A," two octaves up, which is four times the frequency of the piano string.d)Calculate the angular frequency for a soprano singing a "high A," two octaves up, which is four times the frequency of the piano string.
The period and angular frequency of a piano string playing a middle A and a soprano singing a high A are calculated using the given frequencies.
Explanation:a) To calculate the period of a wave, we can use the formula: period = 1/frequency. In this case, the frequency is 220 Hz. Therefore, the period is 1/220 s, which is approximately 0.0045 s.
b) The angular frequency, represented by the symbol ω, is equal to 2π times the frequency. So, for the piano string with a frequency of 220 Hz, the angular frequency is 2π * 220 rad/s.
c) For a soprano singing a high A two octaves up, which has a frequency four times that of the piano string, the period would be 1/ (4 * 220) s.
d) Finally, to calculate the angular frequency for the soprano singing a high A two octaves up, we multiply the frequency by 2π. Therefore, the angular frequency is 2π * (4 * 220) rad/s.
Learn more about Period and Angular Frequency here:https://brainly.com/question/35441793
#SPJ11
what type of device is a car engine?
A.A heat pump that uses heat to do work
B.A heat engine that uses work to move heat
C.A heat pump that uses work to move heat
D.A heat engine that uses heat to do work
D A heat engine that uses heat to do work
Units used to measure the rate of electron flow in a circuit:
Answer:
Ampere (A)
Explanation:
The rate of electron flow in a circuit corresponds to the current in the circuit, defined as:
[tex]I=\frac{Q}{t}[/tex]
where Q is the amount of charge that passes through a given point in the circuit in a time interval of t.
The charge Q is measured in Coulombs (C), while the time t is measured in seconds (s), so the unit of measurement of the current is
[tex][I]=\frac{[C]}{[s]}[/tex]
and this unit is called Ampere, and it is indicated with [A].
Industrialized countries have begun to look at sustainable forms of energy to use to replace more harmful methods, yet poorer countries are more likely to use sources that are cheaper and easier to access. In this context, which of the following would be a more likely option in a poorer country? biomass coal hydroelectric solar
The correct answer is - coal.
The poorer countries do not put a lot of effort to protect the environment and not pollute it. The main reason for this is that they are struggling with poverty, thus they choose no means when it comes to making more profit. This leads to the usage of cheaper and easier to access natural resources in order to produce energy, as they make the most sense to make more profit. From the suggested options, the coal is the most likely source of energy to be used in poorer countries. The coal is cheap, it is found in lot of places around the world, and it is found in abundance. It is also a very powerful source of energy, and that is exactly what the economies of the poorer countries look for.
Determine the pressure acting on a surface of area equal to 2 m2 if the force applied to the surface is 4 N
Answer:
2 N/m²
Explanation:
Pressure is defined as the force acting on a unit area .
Therefore;
Pressure = Force /Area
Force = 4 N
Area = 2 m²
Therefore;
Pressure = 4 N/ 2m²
= 2 N/m²
Early black-and-white television sets used an electron beam to draw a picture on the screen. The electrons in the beam were accelerated by a voltage of 3.0 kV m kV; the beam was then steered to different points on the screen by coils of wire that produced a magnetic field of up to 0.67T
A
What is the speed of electrons in the beam?
B
What acceleration do they experience due to the magnetic field, assuming that it is perpendicular to their path? What is this acceleration in units of g Image for Early black-and-white television sets used an electron beam to draw a picture on the screen. The electrons in?
C
If the electrons were to complete a full circular orbit, what would be the radius?
A) [tex]3.25\cdot 10^7 m/s[/tex]
Assuming the electrons start from rest, their final kinetic energy is equal to the electric potential energy lost while moving through the potential difference [tex]\Delta V[/tex]:
[tex]K=\frac{1}{2}mv^2 = q\Delta V[/tex]
where
[tex]m=9.11\cdot 10^{-31}kg[/tex] is the mass of each electron
v is the final speed of the electrons
[tex]q=1.6\cdot 10^{-19}C[/tex] is the charge of the electrons
[tex]\Delta V=3.0 kV=3000 V[/tex] is the potential difference
Solving the equation for v, the speed, we find
[tex]v=\sqrt{\frac{2q\Delta V}{m}}=\sqrt{\frac{2(1.6\cdot 10^{-19}C)(3000 V)}{9.11\cdot 10^{-31} kg}}=3.25\cdot 10^7 m/s[/tex]
B) Centripetal acceleration, [tex]3.82\cdot 10^4 m/s^2[/tex], in units of g: 3898 g
When the electrons cross the region of the magnetic field, they experience a magnetic force which is perpendicular to their trajectory: therefore they start moving in a circular motion. The acceleration they experience is not tangential, but centripetal, and it is given by
[tex]a_c = \frac{v^2}{r}[/tex]
where v is the speed and r the radius of the trajectory.
We can equate the magnetic force exerted on the electrons to the centripetal force:
[tex]qvB=ma_c[/tex]
and isolate [tex]a_c[/tex] to find the centripetal acceleration:
[tex]a_c = \frac{qvB}{m}=\frac{(1.6\cdot 10^{-19} C)(3.25\cdot 10^7 m/s)(0.67 T)}{9.11\cdot 10^{-31} kg}=3.82\cdot 10^4 m/s^2[/tex]
And since [tex]g=9.81 m/s^2[/tex], the acceleration can be rewritten as
[tex]a_c = \frac{3.82\cdot 10^4 m/s^2}{9.81 m/s^2}=3898 g[/tex]
c) [tex]2.76\cdot 10^{10} m[/tex]
The radius of the circular trajectory can be found by using the formula for the centripetal acceleration:
[tex]a_c = \frac{v^2}{r}[/tex]
Solvign for r, we find
[tex]r=\frac{v^2}{a_c}=\frac{(3.25\cdot 10^7 m/s)^2}{3.82\cdot 10^4 m/s^2}=2.76\cdot 10^{10} m[/tex]
Final answer:
In a black-and-white CRT television, electrons are accelerated by a voltage and then steered by a magnetic field. The speed of electrons can be found using a known formula, and the centripetal acceleration they experience is due to the magnetic force. The radius of their circular path is also calculable from the electron's mass, velocity, and the magnetic field strength.
Explanation:
When electrons are accelerated by a voltage of 3.0 kV (kilovolts) in a black-and-white CRT (cathode-ray tube) television, they gain kinetic energy that is converted from the electric potential energy supplied by the voltage. The formula to find the speed of an electron after acceleration is given by №(√m·V·e), where e is the charge of the electron (1.60 x 10-19 C) and m is the mass of the electron (9.11 x 10-31 kg). The speed is then given by velocity = √(2·V·e/m). Plugging in the numbers, we can find the speed of the electrons.
Regarding part B, since the magnetic force acts perpendicular to the velocity of the electrons, it does not do work on the electrons, meaning the speed of the electrons does not change, but rather, the direction of their velocity changes. Therefore, the acceleration the electrons experience is centripetal acceleration, which keeps the electrons in a circular path, and is given by ac = v2/r, where v is the velocity and r is the radius. To compare this acceleration to g (the acceleration due to gravity), we need the ratio ac/g.
The radius of the circular path, when the electron completes a full circular orbit influenced by a magnetic field, can be determined using the formula r = m·v/(e·B), where B is the magnetic field strength. The radius provides us with valuable information about the steering mechanism in the CRT display.
When unbalanced forces act on an object, __________________. the object accelerates friction becomes greater than the net force the objects speeds up the net force is zero?
When an unbalanced force acts on an object, the object accelerates. We can immediately rule out B and D, as friction changes based on the material and by applying a force the net force can’t be zero. It can be easy to say that the object will speed up after the force is applied (and it often does!), but take a braking car, for example. An external force of friction is applied to the brakes, causing an acceleration but in such a fashion that the car slows down. So, although an object can speed up after a force is applied, it isn’t always guaranteed.
Hope this helps!
Why would it be useful for a house to have sound-absorbing materials in the walls
Hey,
i am here to help you................
The house needs sound absorbing materials in the walls so that reveberation dosen't happens and can here clearly what people will be saying in the house
It is also used in cinema halls also
I believe that this answer was heplful.
(a) A box with its contents has a total mass of 20 kg. It is dropped from a very high building. After reaching terminal speed, what is the magnitude of the air resistance force acting upward on the falling box? N (b) The box survived the fall and is returned to the top of the building. More objects are put into the box, and the box with its contents now has a total mass of 65 kg. The box is dropped, and it reaches a higher terminal speed than before. After reaching terminal speed, what is the magnitude of the air resistance force acting upward on the falling box? (The fact that the heavier object reaches a higher terminal speed shows that the air resistance force increases with increasing speed.)
(a) 196 N
At terminal speed, the velocity of the box is constant: this means that its acceleration is zero, so according to Newton's second Law, the resultant of the forces acting on the box is zero. Since there are only two forces acting on the box:
- The weight, acting downward: [tex]W = mg[/tex]
- The air resistance, acting upward: [tex]R[/tex]
It means that at terminal speed, the two forces are balanced:
[tex]W-R=0[/tex]
So we have:
[tex]R=W=mg=(20 kg)(9.8 m/s^2)=196 N[/tex]
(b) 637 N
The exercise is exactly identical as before, but this time the mass of the box is different: m = 65 kg. Therefore, the air resistance in this case will be:
[tex]R=W=mg=(65 kg)(9.8 m/s^2)=637 N[/tex]
At terminal speed, the air resistance force matches the gravitational force acting on the object. For a 20 kg box, the force is 196 N, and for a 65 kg box, it is 637 N. This shows that air resistance increases with speed and mass.
Air Resistance and Terminal Speed
When an object falls from a height, it initially accelerates due to gravity. However, as its speed increases, the air resistance acting upwards on it also increases. Eventually, the air resistance force becomes equal to the force of gravity, and the object stops accelerating; this constant speed is known as terminal velocity.
(a) Terminal Speed for 20 kg Box
For the box with a mass of 20 kg, the force of gravity (weight) is given by:
[tex]F_{gravity}[/tex] = m imes g
where m = 20 kg and g = 9.8 m/s² (acceleration due to gravity).
Therefore, the weight of the box is:
[tex]F_{gravity}[/tex] = 20 kg imes 9.8 m/s² = 196 N
When the box reaches terminal speed, the air resistance force acting upwards is equal in magnitude to the force of gravity acting downwards. Thus, the magnitude of the air resistance force is: 196 N
(b) Terminal Speed for 65 kg Box
For the box with a mass of 65 kg, the force of gravity is:
[tex]F_{gravity}[/tex] = 65 kg imes 9.8 m/s² = 637 N
At terminal speed, the air resistance force acting upwards balances the weight of the box. Thus, the magnitude of the air resistance force is: 637 N
In summary, the air resistance force is equal to the gravitational force acting on the object at terminal velocity, which depends on the mass of the object.
A resistor, an inductor, and a capacitor are connected in series to an AC source. What is the condition for resonance to occur?
The resistance must be equal to both the inductive reactance and the capacitive reactance.
The capacitive reactance must be greater than the inductive reactance.
The inductive reactance must be greater than the capacitive reactance.
The resistance must be greater than the inductive reactance.
The resistance must be greater than the capacitive reactance.
The capacitive reactance must be equal to the inductive reactance.
The last choice is the correct one.
Resonance in an electrical circuit comprising a resistor, an inductor, and a capacitor connected in series occurs when the inductive reactance equals the capacitive reactance. These reactances represent the effective resistance offered to alternating current by capacitors and inductors, respectively.
Explanation:In an electrical circuit containing a resistor, an inductor, and a capacitor connected in series, resonance occurs when the inductive reactance equals the capacitive reactance. Reactance is a term used to describe the magnitude of the effective resistance offered by an inductor or a capacitor to the alternating current (AC). The capacitive reactance (Xc) varies inversely with the frequency of the AC and the capacitance, while the inductive reactance (Xl) varies directly with both the AC frequency and the inductance. In resonance, these two values balance each other out, resulting in the circuit behaving as if only the resistance is present.
Learn more about Resonance in AC circuits here:https://brainly.com/question/28344758
#SPJ3
An electron has an initial speed of 5.85 106 m/s in a uniform 5.55 105 N/C strength electric field. The field accelerates the electron in the direction opposite to its initial velocity. (a) What is the direction of the electric field? opposite direction to the electron's initial velocity same direction as the electron's initial velocity not enough information to decide (b) How far does the electron travel before coming to rest? m (c) How long does it take the electron to come to rest? s (d) What is the electron's speed when it returns to its starting point? m/s
(a) same direction as the electron's initial velocity
The direction of the acceleration is opposite to the direction of the velocity of the electron. This means that the electron is feeling a repulsive force, in a direction opposite to its initial velocity.
For a negative charge, we know that the electrostatic force and the electric field have opposite directions, because in the formula
[tex]F=qE[/tex]
q is negative. Therefore, the electric field must be in the same direction as the initial velocity of the electron.
(b) [tex]1.76\cdot 10^{-4}m[/tex]
When the electron comes to rest, all its initial kinetic energy has been converted into electric potential energy. So we can write
[tex]K = \Delta U[/tex]
[tex]\frac{1}{2}mv^2= qEd[/tex]
where
[tex]m=9.11\cdot 10^{-31} kg[/tex] is the electron mass
[tex]v=5.85\cdot 10^6 m/s[/tex] is the electron initial speed
[tex]q=1.6\cdot 10^{-19}C[/tex] is the magnitude of the electron charge
[tex]E=5.55\cdot 10^5 N/C[/tex] is the electric field
[tex]d[/tex] is the distance covered
Solving the equation for d, we find
[tex]d=\frac{mv^2}{2qE}=\frac{(9.11\cdot 10^{-31} kg)(5.85\cdot 10^6 m/s)^2}{2(1.6\cdot 10^{-19}C)(5.55\cdot 10^5 N/C)}=1.76\cdot 10^{-4}m[/tex]
which corresponds to 0.17 mm.
(c) [tex]6\cdot 10^{-11} s[/tex]
First of all, we need to find the electrostatic force acting on the electron:
[tex]F=qE=(-1.6\cdot 10^{-16}C)(5.55\cdot 10^5 N/C)=-8.88\cdot 10^{-14} N[/tex]
Now we can find the acceleration of the electron:
[tex]a=\frac{F}{m}=\frac{-8.88\cdot 10^{14} N}{9.11\cdot 10^{-31} kg}=-9.75\cdot 10^{16} m/s^2[/tex]
(the acceleration is negative because it is opposite to the electron's direction of motion)
And now we can find the time taken for the electron to stop to a velocity of v=0 starting from [tex]u=5.85\cdot 10^6 m/s[/tex]:
[tex]a=\frac{v-u}{t}\\t=\frac{v-u}{a}=\frac{0-(5.85\cdot 10^6 m/s)}{-9.75\cdot 10^{16} m/s^2}=6\cdot 10^{-11} s[/tex]
(d) [tex]5.85\cdot 10^6 m/s[/tex]
When it returns to the starting point, all the electric potential energy gained by the electron through the distance d will be re-converted back into kinetic energy. If there is no loss of energy, therefore, this means that the electron will have the same kinetic energy it had at the beginning of the motion: therefore, its speed will be equal to its initial speed, [tex]5.85\cdot 10^6 m/s[/tex].
You do a certain amount of work on an object initially at rest, and all the work goes into increasing the object’s speed. If you do work W, suppose the object’s final speed is v. What will be the object’s final speed if you do twice as much work? 1. 2 v 2. v/√ 2 3. √ 2 v 4. Still v 5. 4 v
Answer:
[tex]\sqrt{2}v[/tex]
Explanation:
The work done on the object at rest is all converted into kinetic energy, so we can write
[tex]W=\frac{1}{2}mv^2[/tex]
Or, re-arranging for v,
[tex]v=\sqrt{\frac{2W}{m}}[/tex]
where
v is the final speed of the object
W is the work done
m is the object's mass
If the work done on the object is doubled, we have W' = 2W. Substituting into the previous formula, we can find the new final speed of the object:
[tex]v'=\sqrt{\frac{2W'}{m}}=\sqrt{\frac{2(2W)}{m}}=\sqrt{2}\sqrt{\frac{2W}{m}}=\sqrt{2}v[/tex]
So, the new speed of the object is [tex]\sqrt{2}v[/tex].
Suppose the car now accelerates from 0 m/s to 30.0 m/s in 5.00 s. If the wheels have a radius of 24.1 cm, what is their angular acceleration?
6.00 rad/s-2
125 rad/s2
0.25 rad/s2
25.0 rad/s
Answer:
[tex]25.0 rad/s^2[/tex]
Explanation:
First of all, we can calculate the tangential acceleration fo a point on the wheels, which is given by
[tex]a=\frac{v-u}{t}[/tex]
where
v = 30.0 m/s is the final velocity
u = 0 m/s is the initial velocity
t = 5.00 s is the time taken
Substituting,
[tex]a=\frac{30 m/s-0}{5.00 s}=6 m/s^2[/tex]
Now we can find the angular acceleration by using the following equation
[tex]\alpha=\frac{a}{r}[/tex]
where
a is the tangential acceleration
r = 24.1 cm = 0.241 m is the radius of the wheels
Substituting into the formula,
[tex]\alpha=\frac{6 m/s^2}{0.241 m}=24.9 rad/s^2 \sim 25.0 rad/s^2[/tex]
The angular acceleration of the car's wheels, given the radius and linear acceleration, is approximately 24.9 rad/s².
Explanation:The angular acceleration of the wheels of a car can be calculated once we know the linear acceleration and the radius of the wheels. The car accelerates from 0 m/s to 30.0 m/s in 5.00 s, which means that the linear acceleration is 30.0 m/s divided by 5.00 s, or 6.0 m/s². Angular acceleration (α) can be calculated by dividing the linear acceleration (a) by the radius (r) of the wheels, i.e., α = a / r.
Firstly, we need to convert the radius from cm to m because the units of acceleration are in m/s². So, the radius is 24.1 cm = 0.241m. Now, α = 6.0 m/s² / 0.241 m = 24.9 rad/s² (approximately) which will be our final answer.
Learn more about Angular Acceleration here:https://brainly.com/question/30238727
#SPJ3
A bumblebee flying through the air picks up a net charge of +40 pC, due in part to the triboelectric effect (charge transfer by friction) from collision with small dust particles*. The presence of this positive charge on their bodies helps the bumblebees locate negatively charged flowers when foraging for pollen and nectar**. The natural electric field near the surface of the Earth has an average magnitude of 120 N/C and is directed downward. The mass of a typical bumblebee is 0.10 grams. Calculate the ratio of the Coulomb force on the bee to the gravitational force on the bee. Note that (1pC = 10^{-12} C)(1pC=10 −12 C). [For small number answers, use the scientific “E” notation : 0.0076 = 7.6E-3 ]
Answer:
[tex]4.9\cdot 10^{-6}[/tex]
Explanation:
The Coulomb force on the bee is:
[tex]F_E=qE[/tex]
where
[tex]q=40 pC=40\cdot 10^{-12} C[/tex] is the charge of the bee
[tex]E=120 N/C[/tex] is the magnitude of the electric field
Substituting into the formula,
[tex]F_E=(40\cdot 10^{-12} C)(120 N/C)=4.8\cdot 10^{-9} N[/tex]
The gravitational force on the bee is
[tex]F_G = mg[/tex]
where
[tex]m=0.10 g=1\cdot 10^{-4}kg[/tex] is the bee's mass
[tex]g=9.8 m/s^2[/tex] is the gravitational acceleration
Substituting into the formula,
[tex]F_G = mg=(1\cdot 10^{-4}kg)(9.8 m/s^2)=9.8\cdot 10^{-4} N[/tex]
So, the ratio between the two forces is
[tex]\frac{F_E}{F_G}=\frac{4.8\cdot 10^{-9} N}{9.8\cdot 10^{-4} N}=4.9\cdot 10^{-6}[/tex]
An object of mass m rests on a flat table. The earth pulls on this object with a force of magnitude mg. What is the reaction force to this pull?
The reaction force of the object on the flat table will be in upward direction with the same magnitude mg.
Explanation:
According to third law of motion, every action has equal and opposite reactions. So here, the action is the gravitational pull acting downward on the object kept on table with a magnitude of mg.
So as per third law, the reaction of the object will be in opposite direction to the action i.e., the pull will be in the upward direction as reaction to the gravitational pull toward downward direction and the magnitude should be same as mg.
Thus, the reaction exerted by the object on the table for the action of gravitational force of magnitude will be the upward pull of the object from the table with the magnitude mg and as both the action and reaction will be canceling each other, the object will remain at the same position on the table without any motion as there is no unbalanced force in the system.
The reaction force to Earth's gravitational pull on an object is the normal force, which has the same magnitude as the object's weight but in the opposite direction, thereby allowing the object to remain at rest on a table.
Explanation:The reaction force to the pull of Earth on an object with mass m is known as the normal force. According to Newton's third law of motion, for every action, there is an equal and opposite reaction. Therefore, if the Earth is pulling on the object with a force of mg, where g is the acceleration due to gravity (approximately 9.80 m/s² on Earth), then the table must be pushing up on the object with an equal force. This upward force is the normal force exerted by the table on the object, and it has the same magnitude as the weight of the object but in the opposite direction. Thus, the reaction force is mg directed upward. This concept is also evident when we consider the object's weight—the gravitational force on a mass m—which is calculated using the formula F = ma = mg. If there were no reaction force, the object would not remain at rest on the table.