# Astronomy 4

## Unlock all answers in this set

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Which of the following is not changing for someone driving a car in a circle at 30 mph? Question options: A) velocity B) position C) acceleration D) momentum E) none of the above (all are changing)
E) none of the above (all are changing)
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What does a force acting on an object do to that object's motion? Question options: A) A force keeps an object moving at a constant velocity. B) A force changes an object's momentum. C) A force changes an object's acceleration. D) A force changes an object's mass. E) B & C
B) A force changes an object's momentum.
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You are weightless if Question options: A) no force acts on you. B) your acceleration is zero. C) your acceleration is equal to the acceleration due to gravity. D) you are in space. E) A & B
C) your acceleration is equal to the acceleration due to gravity.
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If you take off in a rocket accelerating upward, Question options: A) both your weight and mass decrease. B) both your weight and mass stay the same. C) your mass increases and your weight stays the same. D) your weight increases and your mass stays the same. E) both your weight and mass increase.
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Which of the following was Newton's insight about gravity? Question options: A) It produces a change in an object's direction of motion as well as its speed. B) It is caused by a warping of space-time. C) It is responsible for the motion of the Moon around Earth. D) It produces a change in an object's acceleration.
C) It is responsible for the motion of the Moon around Earth.
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Newton's second law of motion states that Question options: A) the acceleration of an object is equal to its mass divided by the force anything on it. B) the acceleration of an object is equal to the force acting on it divided by its mass. C) the acceleration of an object is equal to its mass times its velocity. D) the acceleration of an object is equal to its mass times the force acting on it.
B) the acceleration of an object is equal to the force acting on it divided by its mass.
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All of Newton's laws of motion express the concept that Question options: A) a force (and only a force) always changes the momentum of an object. B) all of these C) the acceleration of an object depends on its momentum. D) the motion of an object reverses direction when a force acts on it. E) the momentum of an object is always constant.
A) a force (and only a force) always changes the momentum of an object.
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Which of the following describes how a rocket takes off? Question options: A) The escaping rocket exhaust changes the mass of the rocket, giving it upward momentum. B) The rocket exerts a force on the ground, and then the atmosphere, causing it to accelerate upward. C) The burning rocket fuel heats the air beneath the rocket causing it to move upward. D) The backward momentum of the rocket exhaust is canceled by the forward momentum of the rocket.
D) The backward momentum of the rocket exhaust is canceled by the forward momentum of the rocket.
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When two objects collide Question options: A) their combined momentum remain unchanged. B) they exert equal and opposite forces on each other. C) their combined angular momentum remains unchanged. D) their combined energy remains unchanged. E) all of the above
E) all of the above
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What is required to change an object's angular momentum? Question options: A) a force acting opposite to the direction of motion B) It is not possible to change an object's angular momentum. C) a force D) a twisting force E) There is no such thing as "angular" momentum.
D) a twisting force
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The energy of Earth's rotation is an example of Question options: A) kinetic energy. B) radiative energy. C) twisting energy. D) potential energy. E) thermal energy.
A) kinetic energy.
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When a ball is dropped, some of the ball's energy changes from Question options: A) kinetic energy to gravitational potential energy. B) gravitational potential energy to kinetic energy. C) gravitational potential energy to radiative energy. D) radiative energy to kinetic energy.
B) gravitational potential energy to kinetic energy.
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Which of the following processes violates a conservation law? Question options: A) One ball hits a second ball and stops moving while the second ball starts moving in the same direction. B) An object speeds up as it approaches the Sun and turns around it, and then slows down as it moves further away, never to return. C) Mass is converted directly into energy. D) An object orbiting the Sun, and affected only by the Sun's gravity spiraling into the Sun.
D) An object orbiting the Sun, and affected only by the Sun's gravity spiraling into the Sun.
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How does the force of gravity between two objects depend on the distance between the objects? Question options: A) It increases in proportion to the distance. B) It increases in proportion to 1/distance. C) It does not depend on the distance. D) It increases in proportion to the distance squared. E) It increases in proportion to 1/distance squared.
E) It increases in proportion to 1/distance squared.
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What happens to the energy of an object while it follows an unbound orbit around the Sun? Question options: A) The total increases when the object approaches the Sun, and decreases when it recedes from the Sun. B) The total remains constant while gravitational potential energy is converted to kinetic energy as it approaches the Sun. C) The total, kinetic and potential energy remains constant. D) The total remains constant while kinetic energy is converted to gravitational potential energy as it approaches the Sun.
B) The total remains constant while gravitational potential energy is converted to kinetic energy as it approaches the Sun.
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The masses of orbiting objects can be determined from Question options: A) Newton's first law. B) Newton's version of Kepler's third law. C) Newton's version of Kepler's first law. D) Newton's third law. E) Newton's second law.
B) Newton's version of Kepler's third law.
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Objects on bound orbits Question options: A) all of these B) orbit the center of mass of the system. C) follow elliptical orbits. D) stay in orbit around the object they are orbiting.