Chapter 4

Question 1

Speed

Answer 1

How fast an object will go in a specific period of time.

Question 2

Velocity

Answer 2

The speed and direction of an object.

Question 3

Acceleration

Answer 3

The change in the velocity of an object, whether in speed or direction.

Question 4

Momentum

Answer 4

The product of an object’s mass and velocity

Question 5

Acceleration of gravity

Answer 5

The acceleration of a falling object

Question 6

Force

Answer 6

Anything that can cause a change in momentum

Question 7

Net force

Answer 7

The combined effect of all the individual forces acting on an object. If two forces act on an object in opposite directions, the net force would be the remaining force. If two forces act on an object in the same direction, the net force would be the combined amount of both forces.

Question 8

Angular momentum

Answer 8

Momentum attributable to rotation or revolution. The angular momentum of an object moving in a circle of radius r is the product m x v x r

Question 9

Torque

Answer 9

The type of force that can change an object’s angular momentum. You can think of this as a twisting force.

Question 10

Mass

Answer 10

The amount of matter in your body

Question 11

Weight

Answer 11

The force that a scale weighs when you stand on it. Weight depends both on your mass and on the forces (including gravity) acting on your mass.

Question 12

Free-fall

Answer 12

Falling without any resistance to slow you down.

Question 13

Newton’s first law of motion

Answer 13

An object moves at a constant velocity if there is no net force acting upon it.

Question 14

Newton’s second law of motion

Answer 14

force = mass x acceleration (F = ma)
force = rate of change in momentum

Question 15

Newton’s third law of motion

Answer 15

For any force, there is always an equal and opposite reaction force.

Question 16

Conservation of momentum

Answer 16

As long as there are no external forces, the total momentum of interacting objects cannot change; that is, their total momentum is conserved.

Question 17

Conservation of angular momentum

Answer 17

As long as there is no external torque, the total angular momentum of a set of interacting objects cannot change.

Question 18

Angular momentum

Answer 18

Angular momentum = m x v x r

Question 19

Conservation of energy

Answer 19

Energy cannot appear out of nowhere or disappear into nothingness. Objects can gain or lose energy only by exchanging energy with other objects.

Question 20

Kinetic energy

Answer 20

Energy of motion; The energy of a moving object is 1/2mv2(squared)

Question 21

Radiative energy

Answer 21

Energy carried by light

Question 22

Potential energy

Answer 22

Stored energy

Question 23

Joule

Answer 23

The standard unit of energy;

Question 24

Thermal energy

Answer 24

The collective kinetic energy of the many individual particles (atoms and molecules) moving randomly within a substance like a rock or the air or the gas within a distant star.

Question 25

Temperature

Answer 25

The average kinetic energy of the particles

Question 26

Gravitational potential energy

Answer 26

The potential energy of an object based on its mass and how far it can fall as a result of gravity

Question 27

Mass-energy

Answer 27

The potential energy of an object based on its mass.