Definitions

Question 1

Vector

Answer 1

A physical quantity that has both direction and magnitude

Question 2

Scalar

Answer 2

A physical quantity that has only magnitude

Question 3

Resultant vector

Answer 3

The single vector which has the same effect as the original vectors acting together

Question 4

Distance

Answer 4

Length of path travelled

Question 5

Displacement

Answer 5

Change in position

Question 6

Speed

Answer 6

Rate of change of distance

Question 7

Velocity

Answer 7

Rate of change of displacement

Question 8

Acceleration

Answer 8

Rate of change of velocity

Question 9

Weight

Answer 9

The gravitational force that the earth exerts on any object on or near its surface

Question 10

Normal force

Answer 10

The perpendicular force exerted by a surface on an object in contact with ut

Question 11

Frictional force

Answer 11

The force that opposes the motion of an object and acts parallel to the surface with which the object is in contact

Question 12

Newtons first Law

Answer 12

An object continues in a state of rest or uniform velocity unless acted upon by a net or resultant force

Question 13

Inertia

Answer 13

The property of an object that causes it to resist a change in its state of rest or uniform motion

Question 14

Newtons second Law

Answer 14

When a net force is applied to an object of mass, it accelerates in the direction of the net force. The acceleration is directly proportional to the net for and inversely proportional to the mass

Question 15

Newtons third Law

Answer 15

When object A exerts a force on object B, object B simultaneously exerts a force of equal magnitude on object A

Question 16

Linear momentum

Answer 16

The product of mass and velocity of the object

Question 17

Elastic collision

Answer 17

A collision in which both momentum and kinetic energy is conserved

Question 18

Inelastic collision

Answer 18

A collision in which only momentum is conserved

Question 19

Impulse

Answer 19

The product of the net force and the contact time

Question 20

Work done on an object by a force

Answer 20

The product of the displacement and the component of force parallel to the displacement

Question 21

Gravitational potential energy

Answer 21

The energy an object possesses due to its position relative to a reference point

Question 22

Kinetic energy

Answer 22

The energy an object has a result of the objects motion

Question 23

Mechanical energy

Answer 23

The sum of gravitational potential and kinetic energy at a point

Question 24

Work energy theorem

Answer 24

The work done by a net force on an object is equal to the change in the kinetic energy of the object

Question 25

Power

Answer 25

The rate at which work is done

Question 26

One watt

Answer 26

The power when one joule of work is done in one second

Question 27

Efficiency

Answer 27

The ratio of output power to input power

Question 28

Newtons law of Universal Gravitation

Answer 28

Every particle with mass in the universe attracts every other particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers

Question 29

Gravitational field

Answer 29

The force acting per unit mass

Question 30

Coulomb’s Law

Answer 30

Two point charges in free space or air exert forces on each other. The force is directly proportional to the product of the charges and inversely proportional to the square of the distance between the charges.

Question 31

Magnitude of the electric field at a point

Answer 31

The force per unit positive charge

Question 32

Potential difference

Answer 32

The work done per unit positive charge

Question 33

Current

Answer 33

The rate of flow of charge

Question 34

Ohm’s Law

Answer 34

Current through a conductor is directly proportional to the potential difference across the conductor at constant temperature

Question 35

Resistance

Answer 35

A materials opposition to the flow of electric current

Question 36

EMF

Answer 36

The total energy supplied per coulomb of charge by the cell

Question 37

Magnetic flux linkage

Answer 37

The product of the number of turns on the coil and the flux through the coil

Question 38

Faraday’s Law of electromagnetic induction

Answer 38

The emf induced is directly proportional to the rate of change of magnetic flux

Question 39

Lenz’s Law

Answer 39

The induced current flows in a direction so as to set up a magnetic field to oppose the change in magnetic flux

Question 40

Diode

Answer 40

A component that only allows current to flow in one direction

Question 41

Threshold frequency

Answer 41

The minimum frequency of incident radiation at which electrons will be emitted from a particular metal

Question 42

Work function

Answer 42

The minimum amount of energy required to emit an electron from the surface of a metal and know that the work function is material specific