Gravity

__________ describes how an orbiting object moves horizontally over the surface of the body it is orbiting.

• The motion of light

• Tangential motion

• Rotational motion

__________ is the amount of substance of an object.

• Mass

• Weight

• Speed

As an object moves away from Earth's center, Earth's gravitational force __________.

• increases

• decreases

• stays the same

Because weight is simply a measure of gravitational force, a person on the Moon would weigh __________ he or she would on Earth.

• more than

• the same as

• less than

Just as satellites orbit Earth, Earth and the other nine planets are actually in orbit around the __________.

• galaxy

• Moon

• Sun

The force that holds together everything from planets to stars to entire galaxies is __________.

• Earth

• gravity

• weight

The Moon appears to simply hang in the sky, but is actually __________.

• revolving around Earth

• moving toward the Sun

• both A and B

• none of the above

When a satellite is in orbit around Earth, why doesn't it fall down to Earth?

• because Earth's gravity doesn't extend outside its atmosphere

• because Earth's gravity repels the satellite

• because the satellite is actually moving in a straight line while simultaneously being pulled by gravity

Gravity is the ______ force in the universe.

• strongest

• second strongest

• second weakest

• weakest

Unlike the electromagnetic force, gravity CANNOT _____.

• be attractive

• be repulsive

• be responsible for holding things together

• draw things together