Chapter 8 Glossary Terms

Question 1

Displacement

Answer 1

A measurement of the change in position of a moving body; a straight line connecting the start and end points is specified in the terms of length and direction.

Question 2

Distance

Answer 2

A measurement of how far away objects are

Question 3

Error

Answer 3

The difference between the value measured and the actual measurement

Question 4

Gradient

Answer 4

Slope of a hill/line.

Gradient= rise/run

Question 5

Instantaneous speed

Answer 5

The speed of an object at a particular moment

Question 6

Precision

Answer 6

How close measured values are to each other

Question 7

Random error

Answer 7

Error that changes

Question 8

Reaction distance

Answer 8

Distance moved when reacting to an emergency

Question 9

Reaction time

Answer 9

The length of time it takes a driver to respond to a hazard

Question 10

Scalar quantity

Answer 10

A quantity like distance or time that has size but not direction

Question 11

Speed

Answer 11

The rate of change of distance

Question 12

Systematic error

Answer 12

Error that always differs by the same amount

Question 13

Vector Quantity

Answer 13

A quantity like displacement or velocity, that has size and direction

Question 14

Velocity

Answer 14

The rate of change of displacement

Question 15

Acceleration

Answer 15

The rate of change of velocity

Question 16

Air resistance

Answer 16

Friction between the air and a moving object

Question 17

Terminal velocity

Answer 17

The final velocity that an object falls with no further acceleration possible due to air resistance.

Question 18

Inertia

Answer 18

The tendency of an object to resist changes in its motion

Question 19

Newton’s First Law of Motion

Answer 19

An object at rest will always remain this way unless it is acted upon by an unbalanced force; an object that is moving will continue to move in the same manner unless acted upon by an unbalanced force.

Question 20

Newton’s Second Law of Motion

Answer 20

An object will accelerate in the direction of an unbalanced force acting upon it such that:

F net= m x a

Question 21

Newton’s Third Law of Motion

Answer 21

For every action there is an equal and opposite reaction.

Question 22

Efficiency

Answer 22

Measure of the useful energy output of an energy transfer.

Question 23

Elastic potential energy

Answer 23

energy stored in a stretched or compressed material, like string or an elastic band.

Question 24

Gravitational potential energy

Answer 24

the potential energy possessed by an object due to its position above the ground

Question 25

kinetic energy

Answer 25

the energy of a moving body

Question 26

Law of Conservation of energy

Answer 26

Energy can be transferred but is never created nor destroyed.

Question 27

Potential energy

Answer 27

energy possessed by an object because of its position of structure or its stored energy

Question 28

Power

Answer 28

The rate at which work is done; measured in watts (W)

Question 29

Work

Answer 29

The energy transferred by a force that acts over a certain distance; measured in joules (J)