Chapter 4

Question 1

Motion

Answer 1

an objects change in positiion relative to a reference point

Question 2

Speed

Answer 2

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

Question 3

Velocity

Answer 3

the speed of an object in a particular direction

Question 4

Acceleration

Answer 4

the rate at which velocity changes over time; an object accelerates if its speed, direction, or both change

Question 5

Force

Answer 5

a push or pull exerted on an object in order to change the motion of the object; force has size and direction

Question 6

Newton

Answer 6

the SI unit for force

Question 7

Net force

Answer 7

the combination of all the forces acting on an object

Question 8

Friction

Answer 8

a force that opposes motion between two surfaces that are in contact

Question 9

Gravity

Answer 9

a force of attraction between objects that is due to their masses

Question 10

Weight

Answer 10

a measure of the gravitational force exerted on an object; its value can change with the location of the object

Question 11

Mass

Answer 11

a measure of the amount of matter in an object