. Chemical energy into kinetic energyd.
A heavy boy and a lightweight girl are balanced on a massless seesaw. The boy moves backward, increasing his distance from the pivot point. What happens to the seesaw? a.It is impossible to predict without knowing additional information. b. The side the boy is sitting on will tilt downward. c. The side the girl is sitting on will tilt downward.d. Nothing; the seesaw will remain balanced.
Answer:
b. The side the boy is sitting on will tilt downward
Explanation:
Initially, the seesaw is balanced because the torque exerted by the boy is equal to the torque exerted by the girl:
[tex]\tau_b = \tau_g\\W_b d_b = W_g d_g[/tex]
where
Wb is the weight of the boy
db is the distance of the boy from the pivot
Wg is the weight of the girl
dg is the distance of the girl from the pivot
When the boy moves backward, the distance of the boy from the pivot ([tex](d_b)[/tex] increases, therefore the torques are no longer balanced: the torque exerted by the boy will be larger, and therefore the side of the boy will tilt downward.
When an object is lifted 6 meters off the ground, it gains a certain amount of potential energy. If the same object is lifted 12 meters off the ground, its potential energy is
When the object is lifted 6 meters of the ground , then lifted to 12 meters, it is lifted twice as high ( 6 x 2 = 12).
This means the potential energy is also doubled.
The potential energy of an object lifted 12 meters off the ground, as opposed to 6 meters, would double, assuming the gravitational field strength and the object's mass stay constant.
Explanation:When discussing potential energy, specifically gravitational potential energy, it is directly related to the height of an object from a reference point, generally the ground. In this scenario of an object being lifted 12 meters instead of 6 meters, the potential energy of the object would essentially double. Gravitational potential energy is calculated as the product of the mass, the gravitational field strength, and the height (PE = mg). As the height is doubled, the potential energy would also double assuming the mass of the object and gravitational field strength remain constant.
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The displacement in simple harmonic motion is a maximum when theA) acceleration is zero. D) kinetic energy is a maximum.B) velocity is a maximum. E) potential energy is a minimum.C) velocity is zero.
Answer:
C) velocity is zero.
Explanation:
In a simple harmonic motion, the total mechanical energy of the system (which remains constant in absence of friction) is given by the sum of the elastic potential energy (U) and the kinetic energy (K) at any moment of the motion:
[tex]E=U+K=\frac{1}{2}kx^2+\frac{1}{2}mv^2[/tex]
where
k is the spring constant
x is the displacement
m is the mass
v is the speed
Since E is a constant number, we immediately see from the formula that, when U increases, K decreases, and viceversa. Therefore, the maximum displacement (maximum x), which corresponds to the maximum potential energy U, will occur when K (kinetic energy) is zero. But K=0 means v=0, so when the velocity is also zero.
The power required to exert 4-n force over 3 meters in 2 seconds is
Answer:
6 W
Explanation:
The work done by the force is equal to:
[tex]W=Fd[/tex]
where
F = 4 N is the force exerted
d = 3 m is the displacement
Substituting,
[tex]W=(4 N)(3 m)=12 J[/tex]
The power is equal to the ratio between work done and time taken:
[tex]P=\frac{W}{t}[/tex]
where
W = 12 J is the work done
t = 2 s is the time
Substituting,
[tex]P=\frac{12 J}{2 s}=6 W[/tex]
The power required is 6 Watts.
The question is asking us to calculate the power required to exert a 4-N force over a distance of 3 meters in 2 seconds. To find the power, we can use the formula:
Power = Work / Time
Where work (W) is calculated by:
Work = Force x Distance
In this case, the work done is:
Work = 4 N x 3 m = 12 J (joules)
Now, we divide the work by the time to find the power:
Power = 12 J / 2 s = 6 Watts
LASIK (Laser Assisted in Situ Keratomileusis) is now a common eye surgery in which a laser is used to remove a thin layer of cornea, correcting vision in the eye so glasses or contacts do not need to be worn. Typically, a laser known as an excimer laser is used, with a wavelength of 193 nm, which has been shown to produce high-quality incisions in the delicate tissue of the eye. (a) In what section of the electromagnetic spectrum does a wavelength of 193 nm place this laser? gamma x-ray ultraviolet visible infrared microwave radio wave long wave Correct: Your answer is correct. (b) If such a laser has a power of 8.00 mW, and is turned on for pulses lasting 40.0 ns each, how much energy is delivered by the laser to the eye in each pulse
LASIK, or "laser-assisted in situ keratomileusis," is the most commonly performed laser eye surgery to treat myopia (nearsightedness), hyperopia (farsightedness) and astigmatism.
Like other types of refractive surgery
, the LASIK procedure reshapes the cornea to enable light entering the eye to be properly focused onto the retina for clearer vision.
In most cases, laser eye surgery is pain-free and completed within 15 minutes for both eyes. The results — improved vision without eyeglasses or contact lenses — can usually be seen in as little as 24 hours.
If you're not a good LASIK candidate, a number of other vision correction surgeries are available, such as PRK and LASEK laser eye surgery and phakic IOL surgery. Your eye doctor will determine if one of these procedures is suitable for your condition and, if so, which technique is best.
LASIK surgery uses an excimer laser with a wavelength of 193 nm, which is in the ultraviolet section of the electromagnetic spectrum. The strong absorption of this wavelength allows for greater accuracy in reshaping the cornea while minimizing damage to the lens and retina of the eye.
Explanation:An excimer laser used in LASIK surgery emits electromagnetic radiation with a wavelength of 193 nm. This wavelength places the laser in the ultraviolet section of the electromagnetic spectrum.
The strong absorption of the 193 nm wavelength by corneal tissue allows the laser to deliver its energy precisely to a thin layer of the cornea, resulting in greater accuracy in reshaping the cornea to correct vision defects. The concentrated energy in the thin layer ensures that only the desired tissue is ablated, limiting damage to the lens and retina of the eye.
A relationship betheeen species in which one species benefits and the other is harmed is called
This relationship is called Parasitism
What is the period of 60.0 hz electrical power?
Answer:
0.017 s
Explanation:
The period of a periodic signal is defined as the reciprocal of the frequency:
[tex]T=\frac{1}{f}[/tex]
where
T is the period
f is the frequency
For the electrical power, the frequency is
f = 60.0 Hz
Substituting into the previous equation, we find the period:
[tex]T=\frac{1}{60.0 Hz}=0.017 s[/tex]
The period of 60.0 Hz electrical power is 0.0167 seconds, calculated by taking the inverse of the frequency.
Explanation:The period of an electrical power wave, such as that with a frequency of 60.0 Hz, can be found by taking the inverse of the frequency. In this case, the frequency is 60.0 Hz, meaning the power wave completes 60 cycles per second. To find the period of this electrical power, we use the formula Period (T) = 1/frequency (f), where 'f' is in hertz (Hz). Thus, T = 1/60, which calculates to a period of 0.0167 seconds. This indicates that each cycle of this 60.0 Hz electrical power takes 0.0167 seconds to complete.
Which set of terms below describes sound waves?
A. Transverse and mechanical
B. Longitudinal and electromagnetic
C. Transverse and electromagnetic
D. Longitudinal and mechanical
Answer:
d. Longitudinal and mechanical
Explanation:
i'm pretty sure
Sound waves are correctly described as longitudinal and mechanical. They require a medium to travel, making them mechanical, and vibrate in the same direction as the wave's movement, making them longitudinal.
Explanation:The correct set of terms that describes sound waves is Longitudinal and mechanical. Sound waves are mechanical because they require a medium (like air, water, or a solid substance) in order to travel. They are also longitudinal because the medium's particles vibrate parallel to the direction of the energy transport. This back and forth motion in the same direction of the wave causes compressions (high pressure) and rarefactions (low pressure) within the medium.
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Which of the following is the characteristic of an inelastic collision?a. The total mass is not conservedb. The total energy is not conservedc. The momentum is not conservedd. the kinetic energy is not conservede. Newtons laws do not apply
Answer:
The kinetic energy is not conserved
Explanation:
The difference between an elastic and an inelastic collision is the following:
- In an elastic collision, both the total momentum and the total kinetic energy of the system are conserved
- In an inelastic collision, the total momentum of the system is conserved, while the total kinetic energy is not. The reason for that is that during the collisions between the objects involved in the system, part of the total kinetic energy is dissipated (mainly as thermal energy, heat) due to frictional forces acting between the objects/between the objects and the surfaces.
Therefore, the correct answer is
The kinetic energy is not conserved
Which of these would be best explained by the Doppler effect? A) The change in frequency as you shorten a guitar string. B) The change in pitch heard as an ambulance approaches you. C) The change in volume as a train pulls away from the station. D) The change in speed of a sound wave as it travels from air into water.
Answer: B) The change in pitch heard as an ambulance approaches you.
Explanation: Don't ask me.
Answer:
B
Explanation:
Doppler effect is about the apparent change in frequency. The change in pitch heard as an ambulance approaches you is an example of this
How many vibrations per second are associated with a 101-mhz radio wave?
Answer:
[tex]1.01\cdot 10^8[/tex] vibrations per second
Explanation:
The frequency of a wave corresponds to the number of vibrations per second:
[tex]f=\frac{N}{1 s}[/tex] (1)
where N is the number of vibrations per second.
In this problem, the frequency of the radio wave is
[tex]f=101 MHz =1.01\cdot 10^8 Hz[/tex]
And substituting into eq.(1), we find N:
[tex]N=f \cdot (1 s)=1.01\cdot 10^8[/tex]
A student wants to demonstrate entropy using the songs on her portable music player. What should she do to demonstrate the highest entropy?
A.Play only the classical songs on shuffle.
B.Play all the songs in order by artist.
C.Play all the songs on shuffle.
D.Play all the songs in alphabetical order.
C play all the songs on shuffle. entropy has to do with randomness
Answer:
play all the songs on shuffle APEX
Explanation:
You are going to invent a new device that people can use instead of a microwave to warm up leftovers.
OK. I would build it the same shape and size as a microwave oven, but I would leave out all the normal electronics.
In the side compartment, in place of the electronics, at the top, I would put a little gas flame, like a Bunsen burner. In the bottom of the side compartment, I would put a treadmill with two strong hamsters. Then, I would install ductwork in the compartment so that when the hamsters turn the wheel, some fan-blades along the rim of the wheel would blow the hot air from the gas flame down and into the big food compartment. This would warm the left-overs WITHOUT using electricity from the wall outlet, and without spraying any hazardous high-power RF energy into the kitchen.
Which answer best describes the image seen through the eyepiece of the telescope?
a. A real and enlarged image
b. A virtual and enlarged image
c. A real and reduced image
d. A virtual and reduced image
The image seen through the eyepiece of a telescope is (option D)a virtual and reduced image.
Explanation:The answer to this question is d. A virtual and reduced image. When you look through the eyepiece of a telescope, you see a virtual image, meaning that the image appears to be there but is not actually present. Furthermore, the image is reduced in size because the eyepiece acts as a magnifying lens.
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The image seen through a telescope's eyepiece is a virtual and enlarged image. This is due to the nature of the converging lens used in the eyepiece, which refracts light to enlarge and invert the image.
Explanation:The image that is seen through the eyepiece of the telescope is a virtual and enlarged image. When you look through a telescope, you see a magnified image of the object, but it is not an image that can be projected onto a screen - hence it's termed 'virtual'. This is due to the convex, or 'converging', lens used in the eyepiece of most telescopes. This lens refracts incoming light paths from the objective lens to enlarge and invert the image. So the correct answer to the question 'Which answer best describes the image seen through the eyepiece of the telescope?' would be b. A virtual and enlarged image.
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What is the free-fall acceleration at the surface of the moon?
The acceleration due to gravity is 1.62m/s^2, this is because the moons gravity is 1/6th that of Earth's (9.81m/s^2) hope this helps! you could also use Newton's law of gravity, F=GM/R^2 where g is the universal gravitational constant, M= mass of the object and R=radius. There should be a neg sign in front of the equation since objects in free fall fall downwards from the given object. Hope this Helps........
In one or two paragraphs, describe a dream youve had and the events that took place.
in my dream i had meet my favorite y o u t u b e r ever and he decided to spend they day with me at my grandparents house. i walked out of the bathroom and he was sitting on my bed playing on his phone and my phone buzzed and i checked it he had given me a shout out on i n s t a but then after lunch we went down to the beach right after high-tide and we went skim boarding we then went fishing and played football with J u j u Smith-S c h u s t e r one of his friends and my favorite NFL player. we got back to the house way after dark ( this is when it gets weird) my grand parents were fuming because it was s o o o late and he did a j e d i mind trick type thing and yeah the next morning he brought J u j u and some other famous people\ y o u t u b e r s (D e e e s t r o y i n g Meek Mill S t e e z y Kane and Travis Scott and they rented out the place for us six and they all gave me a shout out on i n s t a and snap THE END
hope this helps with whatever you needed it for
also can you email me at j t b o u v i e r 9 2 7 4 @ g m a i l . c o m
the ones in spaces are because it wont let me post with them
The virtual image produced by a convex mirror is one third the size of the object.(a) If the object is 51 cm in front of the mirror, what is the image distance? (Include the sign of each answer.)cm(b) What is the focal length of this mirror?cm
(a) -17 cm
Magnification equation:
[tex]\frac{h_i}{h_o}=-\frac{q}{p}[/tex]
where
[tex]h_i[/tex] is the size of the image
[tex]h_o[/tex] is the size of the object
[tex]q[/tex] is the distance of the image from the mirror
[tex]p[/tex] is the distance of the object from the mirror
In this problem, we have:
p = 51 cm (the object is 51 cm in front of the mirror)
[tex]\frac{h_i}{h_o}=\frac{1}{3}[/tex]
So, we can find q, the image distance:
[tex]q=-\frac{h_i}{h_o}p=-\frac{1}{3}(51 cm)=-17 cm[/tex]
and the negative sign means the image is virtual.
(b) -25.5 cm
Mirror equation:
[tex]\frac{1}{f}=\frac{1}{p}+\frac{1}{q}[/tex]
where
p = 51 cm
q = -17 cm
Substituting and re-arranging the equation, we find the focal length of the mirror:
[tex]\frac{1}{f}=\frac{1}{51 cm}-\frac{1}{17 cm}=-\frac{2}{51 cm}\\f=-\frac{51 cm}{2}=-25.5 cm[/tex]
and the negative sign is due to the fact it is a convex mirror.
PLZ HURRY ON A TIMER!!!!!Which statements explain what happens at deep-ocean trenches? Check all that apply. Crust is formed. Mountains are formed. Seafloor spreading occurs. Crust becomes molten rock. Denser plates slide under lighter plates. MORE THAN ONE ANSWER!!!!!!only qualified answers
Seafloor spreading, Crust becomes molten rock, Crust is formed, all of them I think
Answer:
seafloor spreading occurs. Denser plates slide under the lighter plates.
Explanation:
The oceanic crust bends deep inside and forms deep ocean trenches. The crust here actually sinks into mantle under continental crust through the process called subduction which lasts for million of years. Subduction occurs due to oceanic crust being denser than continental crust.
When is the next total solar eclipse in illinois
April 8, 2024
Eclipse will be total over the southern part of the state. Roughly everything south of Decatur and Springfield.
What is the significance of the word universal in Newton's law of universal gravitation
Hey I am here to help you.
Newton's law of universal gravation states that every particle attracts every other particles in the universe with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers
I believe that this answer was helpful.
The explanation for all types of refraction involves a change in
Answer:
Direction
Explanation:
Explanation for all types of refraction involves a change in direction. Refraction is defined as the change in direction when a wave such as light passes from one medium to another. Refraction is determined by the angle and wavelength at which a wave enters a medium and the density of the medium.Therefore, when light passes from a more dense to a less dense medium, the light will be refracted away from the normal.Answer:
Direction
Explanation:
Refraction: It is a process in which when a light ray passes from one medium to another medium then the direction of light ray changes.
Refraction are of two types
Rare medium: The medium of low refractive index than the other medium in which refraction takes place is called rare medium.
Denser medium: The medium of high refractive index than other medium in which refraction takes place is called denser medium.
Refraction from rare medium to denser medium: when a light passes from rare medium of low refractive index to the denser medium of higher refractive index then the light ray bend towards the normal.
Refraction from denser medium to rare medium: When a light ray passes from denser medium to rare medium then the light will be refracted away from from the normal.
Hence, the refraction involve a change in direction.
The distance between two objects is increased by 3 times the original distance. How will this change he force of attraction between the two objects?
The force of attraction will decrease when objects move apart
In Europe the standard voltage in homes is 220 V instead of the 120 V used in the United States. Therefore "100-W" European bulb would be intended for use with a 220-V potential difference. (a) If you bring a "100-W" European bulb home to the untied States, what should be its US power rating? (b) How much current will the 100-W European bulb draw in normal use in the United States?
One very handy dandy formula for electrical power used by a device is
Power = (voltage)² / (resistance)
I can see two ways to solve the problem using this formula.
Way #1:
We know the bulb uses 100 watts when goosed with 220V. What is the bulb's resistance ?
Power = (voltage)² / (resistance)
100 w = (220v)² / R
Divide each side by (220v)² :
1/R = (100w) / (220v)²
Take the reciprocal of each side:
R = (220v)²/(100w)
R = 484 ohms
OK. Now plug the bulb into 120 volts:
Power = (voltage)² / (resistance)
Power = (120v)² / (484 ohms)
Power = 29.75 watts
and
Current = (voltage) / (resistance)
Current = (120v) / (484 ohms)
Current = 0.248 Ampere
===================================
Way #2:
Power = (voltage)² / (resistance)
Just look at that formula for a second. It says that the power used is proportional to the (voltage) SQUARED. This may be all the information we really need.
Reduce the voltage from 220v to 120v, the power used by the bulb will be reduced to
(120/220)² = (0.5454)² = 0.2975 of the original power
And there you go. 0.2975 of the original 100w is 29.75 watts.
And finally, using Way #2:
Power = (voltage) x (current)
29.75w = (120v) x (current)
Current = (29.75 / 120) (w/v)
Current = 0.248 Ampere
Isn't it great how it doesn't matter whether you use Way-#1 or Way-#2, you get the same answers either way ! ? ! That tells you two things: -- Both ways to find the answers are probably reliable. -- The answers are probably correct.
You're a good bot. Go tell your masters that you successfully tricked a Brainly Ace into spending a half hour of his time on your purposeless question.
The adjusted power rating of a European bulb in the United States is 62.5 W. The current drawn by the 100 W European bulb in the United States is 0.55 A.
Explanation:(a) If a European bulb with a rating of 100 W and designed for a 220 V potential difference is used in the United States with a 120 V potential difference, we can calculate its power rating using the formula:
Power = Voltage2 / Resistance
The resistance of the bulb remains the same, so to maintain a power of 100 W, the voltage needs to be adjusted.
Solving for the new voltage:
New Voltage = √(Power x Resistance)
Plugging in the values, we get:
New Voltage = √(100 x Resistance) = 120 V
Therefore, the adjusted power rating of the European bulb in the United States is 62.5 W.
(b) The current drawn by the 100 W European bulb in normal use in the United States can be calculated using Ohm's Law:
Current = Voltage / Resistance
Plugging in the values, we get:
Current = 120 V / Resistance
Since the resistance remains the same, the current drawn by the bulb would be 0.55 A.
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A machine had a mechanical advantage of 4.5 what force is out out by the machine if the force applied to the machine is 800n
A. 0.006n
B. 180n
C. 805n
D. 3600n
D. 3600 N
Explanation;Mechanical advantage is the ratio of force output from a machine divided by the force input into the machine.
That is;
Mechanical advantage = Output Force/Input Force
In this case;
Input force = 800 N
Thus; Output force = M. A × input force
= 4.5 × 800
= 3600 N
Therefore; the output force by the machine is 3600 N
What type of waves carry energy at a right angle to the direction of the energy flow?
Transverse waves In transverse waves, particles of the medium vibrate to and from in a direction perpendicular to the direction of energy
Hope this answer helps you
The transverse wave carries the energy in the right angle of the direction of the wave's advances.
Transverse waves:It is the in which all points of the wave oscillate perpendicular to the direction of the wave's advances.They do not need the medium to travel.For example- Electromagnetic wavesTherefore, the transverse wave carries the energy in the right angle of the direction of the wave's advances.
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What explanation does general relativity provide for gravity?
Answer:
According to Einstein's theory of relativity, mass causes the curvature of space-time and this curvature is what we call gravity.
This means, fluctuations or disturbances of space-time produced by a massive accelerated body, are able to modify the distances and the dimensions of objects in an imperceptible way .
If we see the space-time as a huge fabric, and place two objects (one more massive than the other), both objects will bend this "fabric" and will be "attracted" to each other. Nevertheless, this "attraction" is due to the bending of the space around each object.
General relativity explains gravity as the curvature of spacetime caused by massive objects. It predicts phenomena like gravitational lensing, time dilation, and gravitational waves, which have been confirmed by experiments.
Explanation:General relativity, a theory proposed by Albert Einstein in 1916, explains gravity as a result of mass warping space and time.
According to general relativity, massive objects like planets and stars cause a curvature in the fabric of spacetime, and this curvature determines the paths of objects moving near them.For example, when light passes close to a massive object, such as a star, it follows a curved path because the spacetime around the star is curved. This effect is known as gravitational lensing.General relativity also predicts the existence of phenomena such as time dilation and gravitational waves, which have been confirmed by experiments. It provides a more accurate and comprehensive understanding of gravity compared to Newton's law of universal gravitation.Learn more about general relativity here:https://brainly.com/question/32769043
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A 1.20-m cylindrical rod of diameter 0.570 cm is connected to a power supply that maintains a constant potential difference of 15.0 V across its ends, while an ammeter measures the current through it. You observe that at room temperature (20.0°C) the ammeter reads 18.6 A, while at 92.0°C it reads 17.5 A. You can ignore any thermal expansion of the rod. (a) Find the resistivity at 20°C for the material of the rod. (b) Find the temperature coefficient of resistivity at 20°C for the material of the rod.
(a) [tex]1.72\cdot 10^{-5} \Omega m[/tex]
The resistance of the rod is given by:
[tex]R=\rho \frac{L}{A}[/tex] (1)
where
[tex]\rho[/tex] is the material resistivity
L = 1.20 m is the length of the rod
A is the cross-sectional area
The radius of the rod is half the diameter: [tex]r=0.570 cm/2=0.285 cm=2.85\cdot 10^{-3} m[/tex], so the cross-sectional area is
[tex]A=\pi r^2=\pi (2.85\cdot 10^{-3} m)^2=2.55\cdot 10^{-5} m^2[/tex]
The resistance at 20°C can be found by using Ohm's law. In fact, we know:
- The voltage at this temperature is V = 15.0 V
- The current at this temperature is I = 18.6 A
So, the resistance is
[tex]R=\frac{V}{I}=\frac{15.0 V}{18.6 A}=0.81 \Omega[/tex]
And now we can re-arrange the eq.(1) to solve for the resistivity:
[tex]\rho=\frac{RA}{L}=\frac{(0.81 \Omega)(2.55\cdot 10^{-5} m^2)}{1.20 m}=1.72\cdot 10^{-5} \Omega m[/tex]
(b) [tex]8.57\cdot 10^{-4} /{\circ}C[/tex]
First of all, let's find the new resistance of the wire at 92.0°C. In this case, the current is
I = 17.5 A
So the resistance is
[tex]R=\frac{V}{I}=\frac{15.0 V}{17.5 A}=0.86 \Omega[/tex]
The equation that gives the change in resistance as a function of the temperature is
[tex]R(T)=R_0 (1+\alpha(T-T_0))[/tex]
where
[tex]R(T)=0.86 \Omega[/tex] is the resistance at the new temperature (92.0°C)
[tex]R_0=0.81 \Omega[/tex] is the resistance at the original temperature (20.0°C)
[tex]\alpha[/tex] is the temperature coefficient of resistivity
[tex]T=92^{\circ}C[/tex]
[tex]T_0 = 20^{\circ}[/tex]
Solving the formula for [tex]\alpha[/tex], we find
[tex]\alpha=\frac{\frac{R(T)}{R_0}-1}{T-T_0}=\frac{\frac{0.86 \Omega}{0.81 \Omega}-1}{92C-20C}=8.57\cdot 10^{-4} /{\circ}C[/tex]
which of the following is the best thermal insulator?
A.Air
B. Aluminum
C.Iron
D.Water
Answer:
A. Air
Explanation:
A thermal insulator is a material that does not let the heat trasmitting through it, or it transmits heat not very efficiently.
Generally, the lower the density of the material, the better insulator the material is: this is because in materials with very low density, particles are very spread apart, so they cannot collide with each other, and so the vibrations of the particles (which determine how hot a substance is) cannot be transmitted very efficiently.
In the options listed in this problem, air is the material with lowest density, therefore it is the best thermal insulator among them.
Answer: A. Air
Explanation: Air is a poor thermal conductor because it's particles are farther apart.
If the current increases in a solenoid, the induced emf acts to
increase the flux.
decrease the flux.
first increase then decrease the flux.
first decrease then increase the flux.
have no effect on the flux.
Final answer:
When the current in a solenoid increases, the induced emf acts to decrease the magnetic flux by Lenz's Law, in an attempt to oppose the change in flux caused by the increased current.
Explanation:
If the current increases in a solenoid, the induced emf acts to decrease the flux. This is due to Lenz's Law, which states that the direction of the induced emf and the resulting current will be such as to oppose the change in magnetic flux that produced them. Therefore, when the current through a solenoid increases, it leads to an increase in the magnetic field and magnetic flux. The induced emf will generate a current that creates a magnetic field in the opposite direction, effectively attempting to decrease the magnetic flux back to its original state. This is how the induced emf maintains the overall stability of the magnetic flux within the solenoid.
It's also important to note that the induced EMF is related to the physical geometry of the device and the rate of change of current. While the number of coils in a solenoid and the rate at which the current changes are both important factors in determining the magnitude of the induced emf, the relationship involves the total change in magnetic flux through the solenoid, which is proportional to the number of turns (coils) in the solenoid.
To the nearest second, how many seconds elapse between when a flash of lightning is seen and when the clap of thunder is heard if the lightning is...
a. a kilometer away?
b. 1 mile away (1.6 km away)?
a. 2.9 s
First of all, we can assume that the light of the lightning reaches us instantaneously, since the speed of light is very large and so light takes a negligible time to reach us.
Secondly, the speed of sound in air is
[tex]v=340 m/s[/tex]
So, the difference in time between the moment we see the flash of the lightning and the moment we hear the thunder is simply given by the time it takes for the sound wave to cover the distance of d = 1 km = 1000 m, so:
[tex]t=\frac{d}{v}=\frac{1000 m}{340 m/s}=2.9 s[/tex]
b. 4.7 s
This part of the exercise is exactly identical to the previous one, except for the fact that this time the distance that the sound should cover is
d = 1.6 km = 1600 m
Therefore, the time difference is
[tex]t=\frac{d}{v}=\frac{1600 m}{340 m/s}=4.7 s[/tex]