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15 Cards in this Set
- Front
- Back
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Which of the following statements is not a prediction of the general theory of relativity? Time runs slightly slower on the surface of the Sun than on the surface of Earth. The curvature of spacetime can distort the appearance of distant objects. A binary star system with two stars orbiting each other rapidly emits gravitational waves. The Universe has no boundaries and no center. Different observers can disagree about the fundamental structure of spacetime. |
Different observers can disagree about the fundamental structure of spacetime. |
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What does the equivalence principle say? All observers must always measure the same (equivalent) weights for moving objects. Gravity is the same thing as curvature of spacetime. You cannot distinguish between motion at constant velocity and weight in a gravitational field. The effects of gravity are exactly equivalent to the effects of acceleration. The effects of relativity are exactly equivalent to those predicted by Newton's laws of motion. |
The effects of gravity are exactly equivalent to the effects of acceleration. |
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Jackie is floating freely in her spacecraft, and you are accelerating away from her with an acceleration of lg. How will you feel in your spacecraft? You will be floating weightlessly. You will feel weight, but more than on Earth. You will feel the same weight as you do on Earth. You will feel weight, but less than on Earth. You will feel yourself pressed against the back of your spaceship with great force, making it difficult to move. |
You will feel the same weight as you do on Earth. |
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Suppose you claim that you are feeling the effects of a gravitational field. How can you explain the fact that Jackie is weightless? She is weightless because she is in free-fall If you are in a gravitational field, then she cannot be weightless. She is weightless because she is moving at constant velocity. She is weightless because she is in a free-float frame. |
She is weightless because she is in free-fall. |
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Imagine that you are sitting in a closed room (no windows, no doors) when, magically, it is lifted from Earth and sent accelerating through space with an acceleration of lg (9.8 m/s to power of ((2))). According to Einstein's equivalence principle, which of the following is true? You'll feel a force that will cause your head to repeatedly bang into the ceiling. You'll know that you left Earth because you'll be floating weightlessly in your room. You won't feel any change and will have no way to know that you've left Earth. You'll know that you left Earth because when you drop a ball it will fall sideways. |
You won't feel any change and will have no way to know that you've left Earth. |
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What do we mean by dimension in the context of relativity? The number of sides that we can see when we look at an object. The number of independent directions in which movement is possible. The height of an object. The letter used to represent length mathematically. The size of an object. |
The number of independent directions in which movement is possible. |
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If you draw a spacetime diagram, the world line of an object that is stationary in your reference frame is a circle slanted horizontal vertical curved |
vertical |
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If you draw a spacetime diagram, the worldline of an object that is traveling by you at constant speed is horizontal curved slanted a circle vertical |
slanted |
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If you draw a spacetime diagram, the worldline of an object that is accelerating away from you is a circle vertical slanted horizontal curved |
curved |
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Suppose two lines appear to be parallel but eventually meet. What type of geometry are you dealing with? This situation can never occur Flat geometry Saddle-shaped geometry Spherical geometry Euclidean geometry |
Spherical geometry |
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According to general relativity, why does Earth orbit the Sun? Earth and the Sun are connected by a "ropelike" set of invisible, subatomic particles. The mysterious force that we call gravity holds Earth in orbit. Earth is following the straightest path possible, but spacetime is curved in such a way that this path goes around the Sun. |
Earth is following the straightest path possible, but spacetime is curved in such a way that this path goes around the Sun. |
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According to general relativity, a black hole is a place where light travels faster than the normal speed of light. a hole in the observable universe. a place where light travels slower than the normal speed of light. a place where there is no gravity. an object that cannot be seen. |
a hole in the observable universe. |
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According to general relativity, how is time affected by gravity? Time runs slower in stronger gravitational fields. Time runs faster in stronger gravitational fields. Time is not affected by gravity. Time is stopped by any gravitational field. Time is affected by gravity, but not in a predictable way. |
Time runs slower in stronger gravitational fields. |
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What evidence supports the predicted existence of gravitational waves? The orbit of a star system consisting of two neutron stars is slowly decaying, suggesting that energy is being carried away by gravitational waves. Gravitational waves have been detected by observing their effect on large masses suspended on Earth. Gravitational waves are frequently and easily detected by large telescopes. The energy generated by gravitational waves from the Sun can be seen as it is absorbed by Jupiter. Photographs of spacetime show the gravitational waves as ripples that are clearly visible. |
The orbit of a star system consisting of two neutron stars is slowly decaying, suggesting that energy is being carried away by gravitational waves. |
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In the text is a photograph that appears to show four identical galaxies arranged as a cross. What are we really seeing? a picture taken with a poorly make telescope, so that a single large object appears as four fuzzy dots a large galaxy with four central masses that glow brightly four galaxies that are nearly identical because they were born at about the same time four images of a single background galaxy, created by the gravitational lens of a massive foreground galaxy or cluster |
four images of a single background galaxy, created by the gravitational lens of a massive foreground galaxy or cluster |
