# ASTR 1161 Ch 4

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question
Suppose you lived on the Moon. Which of the following would be true? A - Your weight would be less than your weight on Earth, but your mass would be the same as it is on Earth. B - Both your weight and your mass would be the same as they are on Earth. C - Both your weight and your mass would be less than they are on Earth. D - Your mass would be less than your mass on Earth, but your weight would be the same as it is on Earth.
A - Your weight would be less than your weight on Earth, but your mass would be the same as it is on Earth.
question
Which of the following describes a speed, according to an astronomer? a. 20 meters per second, headed north b. 5 light-years c. 40 revolutions per hour d. 10 light-years per 1 million years
d. 10 light-years per 1 million years
question
Suppose you visit another planet: a. Your mass and weight would be the same as they are on Earth. b. Your mass would be the same as on Earth, but your weight would be different. c. Your weight would be the same as on Earth, but your mass would be different.
b. Your mass would be the same as on Earth, but your weight would be different.
question
Which of the following statements is NOT one of Newton's Laws of Motion? a. For any force, there always is an equal and opposite reaction force. b. The rate of change of momentum of an object is equal to the net force applied to the object. c. In the absence of a net force acting upon it, an object moves with constant velocity. d. What goes up must come down.
d. What goes up must come down.
question
Which of the following examples describes a situation where a car is experiencing a net force? a. The car is making a gradual turn. b. The car is stopped on a hill. c. The car is moving at constant speed. d. The car is floating on a stationary boat.
a. The car is making a gradual turn.
question
Suppose that two objects collide. Which of the following things is NOT the same both before and after the collision? a. the total angular momentum of the objects b. the total energy of the objects c. the total momentum of the objects d. the total temperature of the objects
d. the total temperature of the objects
question
When a spinning ice skater pulls in his arms, he spins faster because _________.
his angular momentum must be conserved, so reducing his radius must increase his speed of rotation
question
What does temperature measure?
the average kinetic energy of particles in a substance
question
If you want to make a rocket turn left, you need to
Fire an engine that shoots out gas to the right.
question
Compared to its angular momentum when it is farthest from the Sun, Earth's angular momentum when it is nearest to the Sun is:
The same
question
As an interstellar gas cloud shrinks in size, its gravitational potential energy:
gradually is transformed into other forms of energy.
question
According to the universal law of gravitation, if you triple the distance between two objects, then the gravitational force between them _________.
Decreases by a factor of 9
question
Which statement must be true in order for a rocket to travel from Earth to another planet? a. It must attain escape velocity from Earth. b. It must be launched from space, rather than from the ground. c. It must carry a lot of extra fuel. d. It must have very large engines.
a. It must attain escape velocity from Earth.
question
Which person is weightless? a. A child in the air as she plays on a trampoline. b. A scuba diver exploring a deep-sea wreck. c. An astronaut on the Moon.
a. A child in the air as she plays on a trampoline.
question
Consider the statement "There's no gravity in space." This statement is:
A). Completely false because there is always gravity at some point from the center of earth, stars, solar system, the Milky Way, etc.
question
Why is Newton's version of Kepler's third law so useful to astronomers?
It can be used to determine the masses of many distant objects
question
If Earth were twice as far from the Sun, the force of gravity attracting Earth to the Sun would be: