Question 1 (2 points) What is gravitation?
Question 1 options:

the tendency of objects to move downward

the attraction of any two objects because of their mass

the attraction or repulsion of objects because of their electric charge

the effect of air pressure in pushing objects to the ground
Question 2 (2 points)
Which of these was discovered by Newton?
Question 2 options:

The acceleration caused by gravity is�9.8�m/s/s.

Gravity keeps the planets in their orbits.

The planets move in elliptical orbits around the sun.

The earth orbits the sun, rather than the reverse.
Question 3 (2 points)
How was the gravitational constant�G�first determined?
Question 3 options:

by measuring the force of gravity between two planets

by observing the moon's orbit

by measuring the force of gravity between two objects on the earth

by knowing that the acceleration caused by gravity is�9.8�m/s/s
Question 4 (2 points)
The force of gravity between any two ordinary objects on the earth is .
Question 4 options:

always downward

stronger when closer to the earth

stronger if the objects are more massive

stronger than the force of gravity from the earth
Question 5 (2 points)
Which of these statements is true about the International Space Station in orbit around the earth?
Question 5 options:

The space station exerts a force on the earth toward the space station.

The earth's gravity acts on the space station, but not the reverse.

There is no gravity acting at the height of the space station.

The force of gravity produces the same acceleration for the earth and the space station.
Question 6 (2 points)
Suppose a planet has twice the mass of the Earth and twice the earth's radius. What is the acceleration of an object in free fall on this planet?
Question 6 options:

twice as much as on Earth.

four times as much on Earth.

one half as much as Earth.

one fourth as much as Earth.
Question 7 (2 points)
Which of these does Newton's law of universal gravitation imply?
Question 7 options:

Force is mass times acceleration squared.

There is no gravity inside a space station in orbit.

The earth attracts the moon more strongly than the moon attracts the earth.

The force of the earth's gravity on an object at sea level is stronger than at the top of a mountain.
Question 8 (2 points)
What is a gravitational field?
Question 8 options:

a region of space-time with constant gravity

the region of space-time where the force is equal to�6.67�10?11�N

a region of space-time with a property at each point determined as the gravitational force on any object divided by its mass�m

the force of gravity between any two objects
Question 9 (2 points)
A gravitational field can be represented by
Question 9 options:

field vector arrows pointing in the direction of the gravitational force.

field vector arrows pointing in the direction of the electrical force.

a photo of a large, green field filled with heavy grass.

field vector arrows pointing in random directions based on their mass.
Question 10 (2 points)
What is the magnitude of a gravitational field at a location where an 80 kg astronaut weighs 25 percent what he would weigh on the earth?
Question 10 options:

10 N/kg

2.5 N/kg

20 N/kg

200 N/kg
Question 11 (2 points)
What causes gravitational force in Einstein's theory of general relativity?
Question 11 options:

the way an object with mass placed on a surface bends the surface

the way mass bends space and time

the existence of black holes

reference frames moving at a constant relative velocity
Question 12 (2 points)
A mass of 10.0 kg is in a gravitational field of�3.50�N/kg�. What force acts on the mass?
Question 12 options:

0.35 N

9.8 N

35.0 N

21.6 N