Question 1

During spring tides

Accepted Answer

A)  The Earth,Moon,and Sun are all aligned.
B)  The Moon,Earth,and Sun are all at right angles
C)  Only the Earth is deformed,not the Moon
D)  Day and night are the same interval of time
E)  There is a good chance of a major earthquake A

Question 2

An object speeds up in such a way that its acceleration is constant.What can we say about the force acting on the object?

Accepted Answer

A)  There is no force acting on it
B)  The force acting on it is constant
C)  The force acting on it increases steadily
D)  The force acting on it decreases steadily B

Question 3

Suppose the Earth were moved to Mercury's distance from the Sun (0.4 AU).How would the gravitational force between the Earth and Sun then compare to its present value?

Accepted Answer

A)  It would be the same
B)  It would be about 2.5 times as strong
C)  It would be about 6 times as strong
D)  It would be about 0.4 times as strong C

Question 4

If the distance between two objects is doubled,the force of gravity they exert on each other will

Accepted Answer

A)  Double
B)  Become 1/2 as large
C)  Become 1/4 as large
D)  Remain the same

Question 5

What happens to the angular momentum of a planet as it orbits the Sun?

Accepted Answer

A)  It increases steadily with time
B)  It gradually drops to zero
C)  It increases and decreases as the planet changes speed
D)  It remains constant

Question 6

The force required to keep an object in a circular orbit is directed

Accepted Answer

A)  Away from the center of the circle
B)  In the direction in which the object is moving
C)  In the direction opposite to that in which the object is moving
D)  Toward the center of the circle

Question 7

Suppose an astronaut whose mass is 50 kg pushes herself away from an artificial satellite that has a mass of 500 kg.While she is pushing,the acceleration of the satellite is 1 m/s per second.What is the acceleration of the astronaut?

Accepted Answer

A)  1 m/s per second
B)  10 m/s per second
C)  1/10 m/s per second
D)  100 m/s per second

Question 8

When a force is applied to a body with a mass of 100 kg,the acceleration of the body is 1 m/s/s.If the same force is applied to a body with a mass of 40 kg,what is the acceleration of the body?

Accepted Answer

A)  0.25 m/s/s
B)  1 m/s/s
C)  10 m/s/s
D)  2.5 m/s/s

Question 9

If the diameter of the Earth were suddenly reduced to one-fourth of its present size while its mass remained the same,how would your weight be altered?

Accepted Answer

A)  It would become 4 times as great
B)  It would become 16 times as great
C)  It would become 8 times as great
D)  It would remain unchanged

Question 10

Suppose an artificial satellite is in a circular orbit about the Earth.What can be said about the acceleration of the satellite?

Accepted Answer

A)  Its acceleration is zero
B)  It is accelerating because its speed changes constantly
C)  It is accelerating because its direction changes constantly
D)  We can tell if it is accelerating only if we can measure the force on it

Question 11

Why does the Earth have a tidal bulge on the side opposite the Moon?

Accepted Answer

A)  Lunar gravity is weakest there
B)  There is another object pulling on the Earth in that direction
C)  The Earth rotates fastest on that side
D)  That is where the Moon's repulsive force is strongest

Question 12

A mass of 50 kg is acted on by a force of 200 N.The motion of the object subsequently will be

Accepted Answer

A)  Motion at a constant speed of 0.25 m/sec
B)  Acceleration at a rate of 4 m/sec/sec
C)  Acceleration at a rate of 200 m/sec/sec
D)  Motion at a constant speed of 50 m/sec

Question 13

The mass of an object _____________ from a planet or star.

Accepted Answer

A)  increases with increasing distance
B)  decreases inversely with increasing distance
C)  stays the same with increasing distance
D)  decreases inversely with the square of the distance

Question 14

Suppose the escape velocity of Planet A is 10 km/s.What would be the escape velocity of a Planet B,which is twice as massive and has the same size as Planet A?

Accepted Answer

A)  7 km/s
B)  10 km/s
C)  14 km/s
D)  20 km/s

Question 15

Where are the greatest tidal forces encountered?

Accepted Answer

A)  Near large,massive objects
B)  Near small,massive objects
C)  Near large,rapidly moving objects
D)  Near small,rapidly moving objects

Question 16

If the Earth were orbiting a ten solar mass star,at a distance of 1 astronomical unit,how would its orbital period be affected?

Accepted Answer

A)  It would be unchanged
B)  It would be about 1/3 of a year
C)  It would be about 3 years
D)  It would be about 1/10 of a year

Question 17

Compared with your mass on Earth,your mass on the Moon would be

Accepted Answer

A)  About 6 times more
B)  About 6 times less
C)  About 36 times more
D)  About 36 times less
E)  Exactly the same

Question 18

A comet has a speed that is slightly larger than escape velocity.What path around the Sun will the comet follow?

Accepted Answer

A)  A circle
B)  An ellipse
C)  A parabola
D)  A hyperbola

Question 19

Assume that Saturn is 10 times as far from the Sun as the Earth is,and that it has 100 times the mass of the Earth.The gravitational force between Saturn and the Sun is

Accepted Answer

A)  100 times the force between the Earth and Sun
B)  10 times the force between the Earth and Sun
C)  Equal to the force between the Earth and Sun
D)  1/10 the force between the Earth and Sun
E)  1/100 the force between the Earth and Sun

Question 20

A hockey puck is seen moving north over a frozen pond at a speed of 2m/sec.A while later it is seen moving west at 2m/sec.Which of the following correctly describes the forces acting on the puck?

Accepted Answer

A)  A force has acted,since the direction has changed
B)  No force has acted,since the speed is the same
C)  A force has acted,but only in a northward direction
D)  The above information is insufficient to tell if forces have acted

Exam 5: Gravity and Motion