The discovery of the constant speed of light proved that classical physics was unable to explain more advanced scientific concepts and led to the birth of a new field—modern physics. The Michelson-Morley experiment proved that light moves at a constant speed at all times, regardless of the relative speed of the observer. Discuss why this characteristic makes light unique compared to all other moving objects in the universe. Support your reasoning with at least two concrete examples of other moving object
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What wavelength monochromatic source in the visible region (390 to 710 nm) can be used to constructively reflect off a soap film (n = 1.46) if the film is 77 nm thick?
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Two stars 19 light-years away are barely resolved by a 63 cm (mirror diameter) telescope. 1ly=9.461×1015m.How far apart are the stars? Assume λ = 550 nm and that the resolution is limited by diffraction.
d=_____? m
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A lens system consists of two lenses 14.0 cm
apart. The first lens is convex (converging) and has a focal length
of 6.72 cm. An object is placed 3.29 cm in front
of the first lens and produces an image 7.00 cm behind the
second lens.
Q1:What is the focal length of the second
lens?
A:5.215 cm
Q2:What is the magnification of the final image?
A2:
Please provide A2 and show all work, I already have the correct answer to Q1(5.215cm)
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Why do some gradients change frequencu while others change phase in MRI?
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An optical interferometer can detect a displacement of 0.1?, or ?50nm.
At what speed would a 3.0m stick "shrink" by 50 nm? Hint: Use the binomial approximation.
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8.0 x 10^15 electrons flow through a cross section of silver wire in 340 us with a drift speed of 7.6 x 10^-4m/s .
What is the diameter of the wire?
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Please answer it well.
TRUE or False: Beyound the point of stall, the wing generates zero lift and the airplane falls from the sky.
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An electron collides elastically with a stationary hydrogen atom. The mass of the hydrogen atom is 1837 times that of the electron. Assume that all motion, before and after the collision, occurs along the same straight line. What is the ratio of the kinetic energy of the hydrogen atom after the collision to that of the electron before the collision?
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Sketch a PV diagram and find the work done by the gas during the following stages. (Draw the PV diagram on paper. Your instructor may ask you to turn in this work.)
(a) A gas is expanded from a volume of 1.0 L to 2.6 L at a
constant pressure of 3.1 atm.
J
(b) The gas is then cooled at constant volume until the pressure
falls to 1.8 atm.
J
(c) The gas is then compressed at a constant pressure of 1.8 atm
from a volume of 2.6 L to 1.0 L. [Note: Be careful of the
signs.]
J
(d) The gas is heated until its pressure increases from 1.8 atm to
3.1 atm at a constant volume.
J
(e) Find the net work done during the complete cycle.
J
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1. The primary of a step-up transformer connected to a 120 V source has 200 turns. If the output is 480 V, how many turns does the secondary have?
2. The primary of a step-down transformer connected to a 240 V source has 1500 turns. The secondary has 200 turns. What is the output voltage of this transformer?
3. A laptop computer requires 24 volts to operate properly. A transformer with 600 turns in the primary needs to have how many turns in the secondary to operate the computer from a 120 V source?
4. If the output current for the transformer in the previous problem is 4.5 A, calculate the input current.
5. A transformer has an input of 24 V and an output of 36 V. If the input is changed to 12 V what will the output be?
6. A model electric train requires 12 V to operate. When connected to a household voltage of 120 V, a transformer is needed. If the primary coil has 250 turns, how many turns must the secondary coil have?
7. A transformer has 25 turns in the primary coil and 200 turns in the secondary coil. If 24 V is connected to the primary coil and a 20-Ω device is connected to the secondary coil, calculate the current in Amperes passing through the device.
8. Neon signs need 12,000 V to operate. If a transformer operates off a 240 V source and has 1000 turns in its primary coil, how may turns must the secondary coil have?
9. A power of 200 kW is delivered by power lines with 48,000 V difference between them. Calculate the current, in amps, in these lines.
10. If the lines in problem #9 above, have a resistance of 100-Ω, calculate the change of voltage along each line.
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Your group has the following equipment: An electroscope, a foam tube, fur, a small plastic cup, a small metal cup. You perform the experiments described below and record the outcomes. For each of the experiments, use your understanding of the electric field to explain why each outcome happened.
-Make sure your explanations use the concept of the electric field rather than “opposite charges attract/same charges repel” ideas.
-Draw LARGE charge diagrams to illustrate your explanations. Show the shape of the electric field by including electric field lines.
Experiments:
a. Bring the charged end of a foam tube down toward the top of an uncharged electroscope without touching the electroscope. Outcome: The metal strips separate.
b. Take the charged end of the foam rod away from the top of the uncharged electroscope. Outcome: The metal strips come back together
c. Repeat the first two experiments, only this time a metal can covers the electroscope but doesn’t touch it. Outcome: The metal strips do not separate.
d. Repeat the first two experiments, only this time a glass beaker covers the electroscope but doesn’t touch it. Outcome: The metal strips separate then come back together, but much less significantly than in experiments a. and b.
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Kepler-1625b is the name of a planet found outside our
solar system. Its mass is 3180x larger than Earth and its radius is
9x larger than Earth
(a) What is the gravitational acceleration (little g) on the
surface of this planet?
(b) This planet may have a moon. If it has the same mass of Earth
what is the gravitational force between the planet and moon? If the
moon orbits 400,000 km away how fast does it orbit?
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A 0.550 kg metal cylinder is placed inside the top of a plastic tube, the lower end of which is sealed off by an adjustable plunger, and comes to rest some distance above the plunger. The plastic tube has an inner radius of 7.41 mm, and is frictionless. Neither the plunger nor the metal cylinder allow any air to flow around them. If the plunger is suddenly pushed upwards, increasing the pressure between the plunger and the metal cylinder by a factor of 2.55, what is the initial acceleration of the metal cylinder? Assume the pressure outside of the tube is 1.00 atm.
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1. Based on the centripetal force law, explain why specific speed limit sign is posted on the banked curves of the roads
2. Is it more difficult to do a sit-up with your hands stretched in front of you or with them behind your head? Explain.
3. When would a ball hitting a wall have a greater change in momentum: when it hits the wall and bounces back at the same speed or when it hits and sticks to the wall? Explain.
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