Gravity and Friction

Question 1

Gravity

Answer 1

the force that attracts a body toward the center of the earth, or toward any other physical body having mass. For most purposes Newton’s laws of gravity apply, with minor modifications to take the general theory of relativity into account.

Question 2

Mass

Answer 2

Amount of matter in an object.

Question 3

Weight

Answer 3

a body’s relative mass or the quantity of matter contained by it, giving rise to a downward force; the heaviness of a person or thing.

Question 4

Friction

Answer 4

A force that opposes motion between two surfaces that are in contact.

Question 5

Density

Answer 5

the degree of compactness of a substance.

Question 6

Motion

Answer 6

An object’s change in position relative to a reference point.

Question 7

Reference Point

Answer 7

A location to which another location is compared.

Question 8

Speed

Answer 8

The distance traveled divided by the time interval during which the motion occurred.

Question 9

Velocity

Answer 9

The speed of an object in a particular direction.

Question 10

Acceleration

Answer 10

increase in the rate or speed of something.

Question 11

Inertia

Answer 11

a tendency to do nothing or to remain unchanged.