the answer is C because 10^-3=1/1000 times 2.5=0.0025
The number that represents the standard form given, 2.5x10⁻³, is 0.0025. That is 0.0025 the same as 2.5x10⁻³. Option C is correct.
Understanding Standard FormStandard form can refer to different concepts depending on the context.
Standard Form of a Number:
In mathematics, the standard form of a number refers to a specific way of representing a number using digits and place value. In standard form, also known as scientific notation, a number is expressed as a product of a coefficient (a decimal number greater than or equal to 1 and less than 10) and a power of 10.
For example:
- The number 3,450,000 in standard form is written as 3.45 × 10^6.
- The number 0.0000625 in standard form is written as 6.25 × 10^-5.
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At an auto race, a member of the pit crew stands beside the track. A car approaches him at 100 m/s and emits a sound at frequency 1100Hz. The air is still and the speed of sound is 340mls. What frequency will the pit crew member hear?
A.1560Hz
B.1420Hz
C.1640Hz
D.850Hz
Answer:
A. 1560 Hz
Explanation:
The Doppler effect occur when a source of a wave (like sound) is moving relative to an observer (or when the observer is moving relative to the source). When this happens, the apparent frequency of the sound as heard by the observer is shifted with respect to the real frequency, according to the formula:
[tex]f'=\frac{v}{v-v_s}f[/tex]
where
f' is the apparent frequency
v is the speed of the wave
vs is the velocity of the source relative to the observer (positive if the source is moving towards the observer, negative if it is moving away from the observer)
f is the real frequency of the wave
In this problem, we have the following data:
f = 1100 Hz is the original frequency of the sound
v = 340 m/s is the speed of the sound wave
[tex]v_s = 100 m/s[/tex] is the velocity of the car approaching the pit crew
Substituting these numbers into the formula, we can find the frequency heard by the pit crew:
[tex]f'=\frac{340 m/s}{340 m/s-100 m/s}(1100 Hz)=1558 Hz \sim 1560 Hz[/tex]
Answer: option A. 1560 Hz
Explanation:
Doppler effect is the phenomenon wherein the frequency of the source of the sound is different from what is received. This happens when either of the source or observer or both are relatively in motion.
In the given question, the observer is stationary and the source of sound is moving at the speed of [tex]v_s = 100 m/s[/tex] towards the observer. The frequency of the sound emitted is [tex]f_s = 1100 Hz[/tex]. The frequency heard by the pit crew member would be given by:
[tex]f_o = \frac{V}{V-v_s}f_s[/tex]
[tex]f_o = \frac{340 m/s}{340m/s - 100 m/s}\times 1100 Hz = 1558.3 Hz = 1560 Hz (approx)[/tex]
Thus, the frequency heard by the pit crew would be 1560 Hz. Correct option is A.
What is the name of the thin, dense membrane that covers the outer layer surface of the bone?
The answer is periosteum. Hope this helps!
The periosteum is the thin, dense membrane that covers the outer layer of bones, providing nourishment and playing a key role in bone growth, repair, and remodeling, excluding areas where bones form joints.
The thin, dense membrane that covers the outer layer surface of the bone is called the periosteum. This membrane is vitally important as it contains blood vessels, nerves, and lymphatic vessels that nourish the compact bone beneath it. Notably, the periosteum connects to the bone with strong collagen fibers known as Sharpey's fibers, which are integral in the attachment of tendons and ligaments. Although it covers most of the bone's surface, the periosteum does not cover the areas where bones form joints; these areas are protected by a different type of tissue. The function of the periosteum is not only protective; it also plays a crucial role in bone growth, repair, and remodeling due to its layer of bone-forming cells.
Describe a real-world example in which the amount of potential and kinetic energy change, but the total amount of mechanical energy stays the same.
n physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes.
Final answer:
A pendulum swinging back and forth is an example where the amounts of potential and kinetic energy change, but the total mechanical energy remains constant.
Explanation:
An example of a real-world scenario where the amount of potential and kinetic energy change, but the total amount of mechanical energy stays the same is when a pendulum swings back and forth. As the pendulum swings to its highest point, it has maximum potential energy and minimum kinetic energy. As it swings down, the potential energy decreases and the kinetic energy increases until it reaches its lowest point, where it has maximum kinetic energy and minimum potential energy. However, the total mechanical energy of the pendulum remains constant throughout its motion because there is no significant energy loss due to friction.
In order of decreasing light-transmitting capabilities of materials, which is the correct sequence? A. Transparent -> translucent -> opaque B. Opaque -> transparent -> translucent C. Opaque -> translucent -> transparent D. Translucent -> transparent -> opaque
transparent --> translucent --> opaque
A. Is the correct answer
Answer:
A is the correct answer :)))
Explanation:
A: If a net force greater than 0 N is applied to an electron and to a proton, which one will accelerate more? The mass of an electron is roughly 1 2000 th that of a proton. A) The electron will accelerate more than the proton. B) The proton will accelerate more than the electron. C) Both the proton and the electron will move at a constant speed. D) Both the proton and electron will accelerate by the same amount.
according to newton's second law , net force on an object is the product of mass of the object and the acceleration of the object. the formula is given as
F = ma where F = net force , m = mass and a = acceleration
so acceleration can be given as
a = F/m
for same net force , the acceleration depends on the mass of the object .
greater the mass , smaller will be the acceleration and vice versa.
Since the mass of electron is smaller as compared to the mass of proton, hence the electron will accelerate more as compared to proton.
A) The electron will accelerate more than the proton
A) the electron will accelerate more than the proton.
If the net force is greater than one, SOOO Newton’s second law of motion, an object will accelerate. The mass is inversely proportional to the acceleration. The lower the mass, the faster the acceleration,
hope this helps! :)
the unit of work is what
Work is defined as a force acting on a body in the direction of a displacement. The unit for displacement is the meter, and the unit for a force is the Newton. Therefore, the unit for work is the Newton-meter or joule.
1. Define the following vocabulary terms:
a. Speed:
b. Direction:
c. Velocity:
d. Vector:
e. Position:
f. Acceleration:
g. Force:
h. Newton:
a) Speed: It is the ratio of distance covered and time interval to cover that distance
it is given as [tex]speed = \frac{distance}{time}[/tex]
b) Direction: it will define for vector quantities and shows the required direction for it
c) Velocity : It is rate of change in position or it is ratio of displacement and time
d) Vector : it is a type of physical quantity which will be defined by magnitude and direction both
e) Position : it is defined as the distance with respect to a given reference or origin
f) Acceleration : it is defined by rate of change in velocity.
[tex]a = \frac{v_f - v_i}{\Delta t}[/tex]
g) Force = it is push or pull on an object which will create acceleration to the object
F = ma
it is product of mass and acceleration
h) Newton : it is SI unit of force or we measure force in this unit
The law of reflection states that if the angle of incidence is 40 degrees, the angle of reflection is ___ degrees.
Answer
40 degrees
Explanation
When waves hit a surface they get reflected. The law of reflection states that the angle of incidence is equal to the angle of reflection. In this case, the law of reflection tells us that if the angle of incidence is 40 degrees, the angle of reflection is 40 degrees.
Two forces pull on an object at the same time. Their resultant force is least when the angle between the forces is _________. A. 0° B. 45° C. 90° D. 180°
Two forces pull on an object at the same time. Their resultant force is least when the angle between the forces is 180°.
Answer: Option D
Explanation:
When two forces are acting on an object, two possibilities are there.
(i) Forces acting on the same direction.
(ii) Forces acting o the opposite direction.
When two forces are acting on the same direction, their resultant force will be maximum, but when they are acting on the opposite direction, minimum resultant force will be the outcome (i.e) they are 180 degrees apart.
Two boys want to balance a seesaw perfectly. One boy weighs 120 pounds and is sitting four feet from the fulcrum. The other boy weighs 80 pounds. Where should the lighter boy sit to balance the seesaw?
Basically a distance multiplied by a weight that is equal to the distance that is going to be multiplied by the weight. (for the equation we will use X for the distance).
equation: 4 x1 20 = ? x 80
Now step one: 4(120) = X(80)
Or another way is 480 = 80X
480/80 = X
48/8= X
X = 6
I hope this could help! Sorry if it didn't make much sense otherwise!
Acceleration due to gravity is ( always / sometimes / never ) the same on the earth.
Sometimes, because acceleration due to gravity on Earth depends on how close you are to the Earth's center.
Which direction is the force of friction?
A. The same direction of the movement
B. The opposite direction of the movement
C. 90 degrees from the direction of movement
Friction always acts opposite to the motion. (B)
When using a calorimeter, the initial temperature of a metal is 70.4C. The initial temperature of the water is 23.6C. At the end of the experiment, the final equilibrium temperature of the water is 29.8C.
What is the final temperature of the metal?
C
What is the temperature change of the water?
C
What is the temperature change of the metal?
C
1) 29.8 C
At the beginning, the metal is at higher temperature (70.4 C) while the water is at lower temperature (23.6 C). When they are put in contact, the metal transfers heat to the water, until they reach thermal equilibrium: at thermal equilibrium the two objects (the metal and the water have same temperature). Therefore, since the temperature of the water at thermal equilibrium is 29.8 C, the final temperature of the metal must be the same (29.8 C).
2) 6.2 C
The temperature change of the water is given by the difference between its final temperature and its initial temperature:
[tex]\Delta T = T_f - T_i[/tex]
where
[tex]T_f = 29.8 C\\T_i = 23.6 C[/tex]
Substituting into the formula,
[tex]\Delta T=29.8 C-23.6 C=6.2 C[/tex]
And the positive sign means that the temperature of the water has increased.
3) -40.6 C
The temperature change of the metal is given by the difference between its final temperature and its initial temperature:
[tex]\Delta T = T_f - T_i[/tex]
where
[tex]T_f = 29.8 C\\T_i = 70.4 C[/tex]
Substituting into the formula,
[tex]\Delta T=29.8 C-70.4 C=-40.6 C[/tex]
And the negative sign means the temperature of the metal has decreased.
Answer:
29.8, 6.2, -40.6
Explanation:
2Mg + O2 --> ?? + heat How many atoms would you expect to find on the product side of this equation?
Answer:
[tex]2Mg + O_2 \rightarrow 2MgO + heat[/tex] (2 atoms on the product side)
Explanation:
Due to the law of conservation of mass, in every chemical reaction the number of atoms of each element on the reactant side must be equal to the number of atoms of the same element on the product side.
In this case, on the product side we have magnesium (which has two valence electrons) and oxygen (which has two vacancies in its outer shell). This means that they combine in a ratio 1:1, so the product of the reaction is
[tex]MgO[/tex]
However, we must put a coefficient 2 in front of it in order to balance the number of atoms of each element: in fact, on the reactant side we have 2 atoms of magnesium and 2 of oxygen, so we must have two atoms of magnesium and 2 of oxygen on the product side as well. Therefore, the complete reaction is
[tex]2Mg + O_2 \rightarrow 2MgO + heat[/tex]
Please help me with this! (:
Convert 4.9 m/s to km/h.
A. 18 km/h
B. 49,000 km/h
C. 1.4 km/h
D. 18,000,000 km/h
Answer:
(A) 18 km/h
Explanation:
[tex]4.9\frac{m}{s}=4.9\cdot \frac{\frac{1}{1000}km}{\frac{1}{3600}h}=4.9\cdot3.6\frac{km}{h}=17.64\frac{km}{h}\approx18\frac{km}{h}[/tex]
A 0.28-kg stone you throw rises 34.3 m in the air. The magnitude of the impulse the stone received from your hand while being thrown is
Answer:
7.3 kg m/s
Explanation:
First of all, let's calculate the gravitational potential energy of the stone as it reaches its highest point:
[tex]U=mgh=(0.28 kg)(9.8 m/s^2)(34.3 m)=94.1 J[/tex]
For the law of conservation of energy, this is equal to the initial kinetic energy of the stone at ground level (where the potential energy is zero), just after the stone leaves your hand:
[tex]K=\frac{1}{2}mv^2=94.1 J[/tex]
From this equation we can find the velocity of the stone as it leaves your hand:
[tex]v=\sqrt{\frac{2K}{m}}=\sqrt{\frac{2(94.1 J)}{0.28 kg}}=25.9 m/s[/tex]
The initial velocity of the stone (before leaving your hand) is zero:
[tex]u=0[/tex]
The impulse received by the stone is equal to its change in momentum, so:
[tex]I=\Delta p=m\Delta v=m(v-u)=(0.28 kg)(25.9 m/s-0)=7.3 kg m/s[/tex]
The magnitude of the impulse the stone received from your hand while being thrown is approximately 17.22 kg*m/s, calculated by considering the conversion of its gravitational potential energy into kinetic energy, and consequently finding the change in momentum.
Explanation:Given the mass of the stone (m = 0.28 kg) and the height to which the stone rises (h = 34.3 m), the impulse can be calculated using the relationship between impulse, momentum, and energy.
Firstly, as we're considering a height and a resultant vertical motion, we can approach this in terms of gravitational potential energy for simplicity. The stone's kinetic energy is converted to gravitational potential energy at the highest point of its trajectory. So, the potential energy at peak is mgh, which is equal to 0.28 kg * 9.8 m/s^2 * 34.3 m = 93.0284 Joules.
Considering that the kinetic energy the stone started with (K=0.5mv^2) is equivalent to this potential energy (as no energy is lost, only converted), we can derive the initial velocity using v= sqrt(2*K/m).
Now, plug the knowns in to solve for velocity: v= sqrt((2*93.0284Joules)/0.28kg), which gets us v≈61.5 m/s. The magnitude of the impulse is given by the change in momentum, which in this case is the stone's momentum as it leaves the hand (because it starts at rest). So finally, the impulse is equal to the product of the mass of the object and the change in its velocity (Impulse = mv): Impulse = 0.28 kg * 61.5 m/s = approximately 17.22 kg*m/s (rounded).
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After brushing, Fluffy's fur has a charge of 8.0 x 10^-9 coulombs and her plastic brush has charge of -1.4× 10^-8 coulombs. If the distance between the fur and brush is roughly 5.0 × 10^-1 meters, what is the approximate magnitude of the force between them?
Given data:
charge 1 (q₁) = 8.0 × 10⁻⁹ coulombs
charge 2 (q₂) = -1.4 × 10⁻⁸ coulombs
distance between fur and brush (r) = 5.0 × 10⁻¹ m
We know that,
The couloumb's law describes the charge between two particles
Mathematically,
F = k.(q₁ . q₂)/r² ----------------------- (i)
Where F = Force between particles
k = constant, 8.99 × 10⁹ Nm²/C² -------------- (ii)
keep the charge, distance values and value of k in equation (i), to determine the magnitude of force
F = 8.99 × 10⁹ ×{ (8.0 × 10⁻⁹) × ( -1.4 × 10⁻⁸)} / (5.0 × 10⁻¹)²
= -4.02 × 10⁻⁶
The force is negative means "the force is attractive"
Which statement about how light travels is true? A Light waves need a medium to travel, and they travel at the same speed even if the light source is moving. B Light waves can travel in a vacuum and travel at a constant speed even if the light source is moving. C Light waves can travel in a vacuum and will travel faster if the light source is moving forward. D Light waves need a medium to travel, and they travel faster if the light source is moving forward.
Answer:
Light wave can travel in a vacuum and travel at a contest speed even if the light source is moving
Explanation:
Light waves are electromagnetic waves and they need no medium to travel. The speed of light is constant and does not change with the movement of source.
What is electromagnetic waves?Electromagnetic waves are transfer of energy through vacuum. These electromagnetic waves are associated with specific wavelength, frequency and energy.
Visible light is in between IR and UV waves in electromagnetic spectrum. Light is the fastest moving thing in the world and it does need a medium to travel. The waves which need a medium to propagate is called mechanical waves.
Therefore, the true statement about light is light waves can travel in a vacuum and travel at a constant speed even if the light source is moving. Thus, option B is correct.
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An object placed in water will float if the weight of the object is MORE THAN the buoyant force of the water.
True
False
False
If the object weighs more than the buoyant force then the object will sink.
This is because the buoyant force "pushes" the object upwards and the weight of the object "pushes" the object downwards. Since the force downwards is greater than the force upwards the item will sink, so this statement is False.
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3) A driver in a 1000-kg car traveling at 24 m/s slams on the brakes and skids to a stop. If the coefticient of friction between the tires and the level road is 0 80 how long will the skid marks be? A) 37 m B) 30 m C) 34 m D 46 m
Answer:
A) 37 m
Explanation:
When the driver slams on the brakes, the force of friction acting on the car provides the deceleration that will cause the car to stop, according to Newton's second law:
[tex]-\mu mg = ma[/tex]
where
[tex]\mu = 0.80[/tex] is the coefficient of friction
m = 1000 kg is the mass of the car
g = 9.8 m/s^2
a is the deceleration
Substituting into the formula, we find the deceleration:
[tex]a=- \mu g=-(0.80)(9.8 m/s^2)=-7.84 m/s^2[/tex]
Now we can find the length of the skid with the SUVAT equation:
[tex]v^2 - u^2 = 2ad[/tex]
where
v = 0 is the final velocity of the car
u = 24 m/s is the initial velocity
d is the length of the skid
Substituting, we find
[tex]d=\frac{v^2 -u^2}{2a}=\frac{0-(24 m/s)^2}{2(-7.84 m/s^2)}=36.7 m \sim 37 m[/tex]
How far can a mother push a 20.0 kg baby carriage, using a force of 62.0 N at an angle of 30.0º to the horizontal, if she can do 2920 J of work?
Answer:
54.4 m
Explanation:
The work done by the mother in pushing the carriage is equal to:
[tex]W=Fdcos \theta[/tex]
where
F is the force applied
d is the displacement of the carriage
[tex]\theta[/tex] is the angle between the direction of the force and the displacement
In this problem, we have the following data:
[tex]F=62.0 N[/tex] is the force
[tex]W = 2920 J[/tex] is the work done
[tex]\theta=30.0^{\circ}[/tex] is the angle between the direction of the force and the displacement
Re-arranging the equation above and substituting data, we find the displacement:
[tex]d=\frac{W}{F cos \theta}=\frac{2920 J}{(62.0 N)(cos 30^{\circ})}=54.4 m[/tex]
When a force is applied at an angle, we should consider the horizontal component of the force for any horizontal movement. In this case, the mother can push the baby carriage about 54.5 meters by expending 2920 Joules of work.
Explanation:The subject of the problem involves the concept of work and force in physics. When the mother pushes the baby carriage at an angle, not all of the force she applies is used to move the carriage horizontal. We need to consider the horizontal component of the force which is 62.0N*cos(30.0º) = 53.61047 N. Work is defined as force times the distance over which the force is applied, or in this case, the force times the distance the carriage is pushed. The calculation looks like this:
Work = Force x Distance = 2920 J
Distance = Work / Force = 2920 J / 53.61047 N = 54.48013 m
So the mother can push the baby carriage approximately 54.48013 meters with an expenditure of 2920 joules of work.
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The effectiveness of an optical lens is attributed to:
diffraction
reflection
refraction
interference
refraction is the right answer
Answer: Refraction.
Explanation: The lenses are used to "transmit" the light that hits the lens in a certain way.
The phenomena in which the light penetrates a medium (where the medium, in this case, is the lens) is called diffraction.
Reflection would be more related to mirrors, difraction is the change of the velocity of the light waves when they are in different mediums, and interference refers to the interaction between two coherent waves (it can be destructive interference, where the waves cancel each other, or constructive interference, where the waves add to each other)
Area of orifice is a. Due to ejection of water of density p at a constant speed, the equilibrium compression in spring is x. The speed of ejection of water is...
(Please answer ASAP !)
Thrust force due to ejection of water on the cart is counter balanced by spring force on the cart
so we can write
[tex]F_t = v \frac{dm}{dt}[/tex]
here we have
[tex]\frac{dm}{dt}[/tex] = rate of mass ejection
[tex]\frac{dm}{dt} = \rho a\frac{dx}{dt} = \rho a v[/tex]
now from above formula
[tex]F_t = \rho a v(v) = \rho av^2[/tex]
Now by force balance equation
[tex]F_t = F_s[/tex]
[tex]\rho a v^2 = kx[/tex]
by rearranging the terms now
[tex]v= \sqrt{\frac{kx}{\rho a}}[/tex]
What is the rms speed of nitrogen molecules contained in a 8.5 m3 volume at 3.5 atm if the total amount of nitrogen is 1900 mol ?
The root-mean-square (rms) speed of nitrogen molecules in a given volume and pressure can be calculated using the formula V_rms = sqrt(3kBT/m), where V_rms is the rms speed, T is the temperature in kelvin, k is the Boltzmann constant, and m is the mass of a nitrogen molecule. To solve this problem, we first need to find the temperature using the ideal gas law equation PV = nRT. Once we have the temperature, we can substitute it into the rms speed equation to find the final answer in m/s.
Explanation:The root-mean-square (rms) speed of nitrogen molecules in a given volume and pressure can be calculated using the formula:
Vrms = √( 3kBT/m ), where Vrms is the rms speed, T is the temperature in kelvin, k is the Boltzmann constant (1.38 × 10-23 J/K), and m is the mass of a nitrogen molecule.
In this case, we are given the volume (8.5 m3), pressure (3.5 atm), and total amount of nitrogen (1900 mol). To find the temperature, we need to use the ideal gas law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant (0.0821 atm·L/mol·K), and T is the temperature.
Using the ideal gas law, we can solve for T:
T = PV/(nR)
Substituting the given values, T = (3.5 atm × 8.5 m3)/(1900 mol × 0.0821 atm·L/mol·K) = 16.573 K
Now we can calculate the rms speed:
Vrms = √( 3 × 1.38 × 10-23 J/K × 16.573 K / (28.0067 × 10-3 kg/mol) )
Calculating this expression will give us the rms speed of the nitrogen molecules in m/s.
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The rms speed of nitrogen molecules can be calculated using Boltzmann's constant, nitrogen's molar mass, and the given temperature in Kelvin. By substituting these values into the formula, we can compute the nitrogen molecules' speed.
Explanation:The rms speed (root mean square speed) of nitrogen molecules can be calculated using the formula:
Vrms = sqrt(3kT/m')
where k stands for Boltzmann's constant, T is the temperature in Kelvin, and m' represents the molar mass of nitrogen (N₂) molecule. According to the periodic table, the molar mass of nitrogen N₂ is 2(14.0067)x10-3 kg/mol. Plugging in the values and doing the calculation should give you the rms speed of the nitrogen molecules.
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How do two isotopes of the same element different?
A. They have different numbers of protons.
B. They have different charges.
C. They have different atomic numbers.
D. They have different numbers of neutrons.
D. because Isotopes will have the same atomic number because they are the same element but have a different atomic mass because they contain a different number of neutrons.
Isotopes of the same element differ in the number of neutrons they contain, which leads to different atomic weights but doesn't change the chemical properties of the element.
Explanation:Isotopes are variations of a particular chemical element, which means they will always have the same number of protons and the same atomic number. However, isotopes of the same element differ in their number of neutrons. This can lead to different physical properties, such as mass, but the chemical properties remain largely unaffected because chemical behavior is determined by the number of electrons, which remains constant in isotopes of the same element. For example, Carbon-12 (12C) and Carbon-14 (14C), are both isotopes of Carbon where the number refers to the atomic weight, which changes due to the different numbers of neutrons.
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An train car of total mass of 13000 kg is pulling into a station and slowing down with an acceleration of -4.56 m/s^2. Before the train pulls into the station, a group of 7 stowaway jump off the train. Each stowaway has a mass of 66 kg. If the braking force on the train remains the same, what will be the acceleration of the train once the stowaways jump out of the train?
-4.73 m/s²
Explanation:Each jumper represents about 1/2 of 1% of the mass of the train, so together they total about 3.5% of the mass of the train. If the mass decreases by 3.5% and the braking force remains the same, the acceleration (magnitude) will increase by about 3.5%.
The acceleration will be about 0.17 m/s² more (in magnitude) than it was, or about -4.73 m/s².
a force of 10. N toward the right is exerted on a wooden crate initially moving to the right on a horizontal wooden floor. the crate weight 25 N.
1)calculate the magnitude of the force of friction between the crate and the floor.
2)What is the magnitude of the net force acting on the crate?
3)is the crate accelerating? explain.
1) 5 N
The crate is initially moving, so we must calculate the force of kinetic friction, which is given by:
[tex]F_f = \mu_k mg[/tex]
where
[tex]\mu_k=0.2[/tex] is the coefficient of friction between the crate (made of wood) and the floor (made of wood). The coefficient of kinetic friction between wood and wood is about 0.2.
[tex]mg=25 N[/tex] is the weight of the crate
Substituting the numbers into the formula, we find
[tex]F_f=(0.2)(25 N)=5 N[/tex]
2) 5 N
There are two forces acting on the crate along the horizontal direction:
- The force that pushes the crate toward the right, of magnitude [tex]F=10 N[/tex]
- The force of friction, which acts in the opposite direction (so, towards the left), of magnitude [tex]F_f = 5 N[/tex]
Since the two forces are in opposite directions, the net force is given by their difference:
[tex]F_{net}=F-F_f = 10 N-5 N=5 N[/tex]
3) Yes
The crate is accelerating. In fact, according to Second Newton's Law:
[tex]F_{net}=ma[/tex] (1)
where Fnet is the net force on the crate, m is its mass, a is its acceleration. We can immediately see that since Fnet is not zero, the acceleration is also non-zero, so the crate is accelerating.
We can even calculate the magnitude of the acceleration. In fact, the mass of the crate is given by:
[tex]m=\frac{Weight}{g}=\frac{25 N}{9.8 m/s^2}=2.55 kg[/tex]
And by using (1) we find
[tex]a=\frac{F_{net}}{m}=\frac{5 N}{2.55 kg}=1.96 m/s^2[/tex]
Exact calculations for solving this physics problem are hindered by a lack of information on the coefficient of friction, but it can be asserted that the net force acting on the crate is 10N, and the crate should be accelerating due to this net force.
Explanation:In this scenario we're dealing with the concepts of force, friction, and acceleration from the field of physics. Let's go step by step.
1) The frictional force equals the weight of the crate times the coefficient of friction. But since we are not given the coefficient of friction, we cannot calculate it. However, to calculate it, you would use the following formula: Force of Friction = µ * Weight
2) The net force is simply the sum of all forces. Here, there's only one force acting on the crate in horizontal direction - the force of 10N to the right. Therefore, the Net Force = 10 N.
3) If there's a net force acting on an object, it means the object is accelerating, as per Newton's Second Law of Motion(F=ma). This suggests that the crate is indeed accelerating.
Learn more about Newton's Laws here:https://brainly.com/question/34706880
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Seven-eighths of a sample of hydrogen-3 will have become a stable isotope after 36.9 years. What is the half-life of hydrogen-3? 12.3 years 18.5 years 32.3 years 36.9 years
Answer:
12.3 years
Explanation:
The equation of the radioactive decay can be written as follows:
[tex]\frac{N(t)}{N_0}=(\frac{1}{2})^{\frac{t}{\tau_{1/2}}}[/tex] (1)
where
N(t) is the amount of radioactive sample left at time t
N0 is the amount of radioactive sample at time t=0
t is the time passed
[tex]\tau_{1/2}[/tex] is the half-life of the isotope
The problem tells us that after t=36.9 y, the amount of sample which has become stable is 7/8. This means that 7/8 of the sample has already decayed, so the amount of radioactive sample left is
[tex]\frac{N(t)}{N_0}=1-\frac{7}{8}=\frac{1}{8}[/tex]
We can now re-arrange equation (1) by using this information and by substituting t=36.9 y we find:
[tex]\frac{t}{\tau_{1/2}}=log_{1/2} (\frac{N(t))}{N_0})\\\tau_{1/2}=\frac{t}{log_{1/2}(\frac{N(t)}{N_0})}=\frac{36.9 y}{log_{1/2}(1/8)}=\frac{36.9 y}{3}=12.3 y[/tex]
So, the answer is
12.3 years
Answer:
A. 12.3 years
Explanation:
A friend says that tempature increases as altitude increases because you are moving closer to the sun. Is this true?
No, temperature change in the Earth's atmosphere is related to the distance from the sun, and temperature generally decreases altitude.
Answer:
This is true for some layers of the Earth's atmosphere.
Explanation:
As a counterexample: in the lowest layer of the atmosphere, with the highest density of gases, aka the Troposphere, the temperature decreases with increasing altitude. This relates to the sun heating up the surface some of which radiates back into the Troposphere.
However, the temperature increases with altitude in the Stratosphere (effect of ozone absorbing Sun rays), and it also increases with altitude in the Thermosphere (due to UV rays absorption).
The Mesosphere is another counterexample where the temperature decreases with increasing altitude.
the total amount of force they exert on the box is 500 Newton's . Despite their efforts, the box will not move. What is the amount of force exerted by the box on each person?
Whatever amount of force each person exerts on the box, THAT's the amount of force the box exerts on him. There's no reason the forces of each person have to be equal.
Let's say . . .
-- Mr. Smith pushes on the box with 499.99 newton's of force.
-- Mr. Jones is actually a fly; he pushes on the box with 0.01 newton of force.
The total of their forces is 500 Newtons on the box.
The box exerts 499.99 newtons of force back on Mr. Smith, and 0.01 newton of force back on Mr. Jones, the fly.