Mechanics

Front 1

Define "scalar quantities"

Back 1

Quantities which have magnitude only are called scalar quantities.

Front 2

Define "vector quantities"

Back 2

Quantities which have both magnitude and direction are called vectors.

Front 3

Define displacement

Back 3

Displacement is distance moved in a particular direction.

Front 4

Define instantaneous speed

Back 4

The instantaneous speed of an object is defined as the speed of the object at any given instant.

Front 5

Define average speed

Back 5

The Average speed is the average of the speed of a moving object for the overall distance it has covered.

Front 6

Define velocity

Back 6

Velocity is speed in a specified direction and is defined as the rate of change of displacement.

Front 7

Define acceleration

Back 7

Acceleration is the rate of change of speed or velocity.

Front 8

Define the newton

Back 8

One newton is the force that causes a mass of one kilogram to have an acceleration of one metre per second every second.

Front 9

Explain centre of gravity

Back 9

The centre of gravity of an object is a point where the entire weight of an object appears to act.

Front 10

Define thinking distance

Back 10

The distance travelled by a vehicle between the time that it needs to brake is perceived and the time that the brakes are applied.

Front 11

Define braking distance

Back 11

The distance travelled by the car after the brakes are applied until the car stops.

Front 12

Define stopping distance

Back 12

The distance that a driver drives before they come to a complete stop.

Front 13

Define work done by force

Back 13

Work is measured in joules where one joule is the work done when a force of one newton moves its point of application one metre in the direction of the force.

Front 14

Define the joule

Back 14

One joule is the work done when a force of one newton is used to move a body a distance of one metre in the direction of the force

Front 15

State the principle of conservation of energy

Back 15

The principle of conservation of energy states that energy cannot be created or destroyed.

Front 16

Define power

Back 16

Power is the rate of work done

Front 17

Define the watt

Back 17

One watt is the power dissipated when one joule of work is done in a time of one second.

Front 18

Define the torque of a couple

Back 18

A couple is a pair of equal and parallel yet opposite forces, which tend to produce rotation only. The term torque describes the turning effect of a couple.

Front 19

Define the moment of force

Back 19

The turning effect of a force F about some axis is called its moment.

Front 20

Define stress

Back 20

Stress is a force per unit cross-sectional area.

Front 21

Define strain

Back 21

Strain is extension per unit length.

Front 22

Define young modulus

Back 22

Young's modulus is a measure of the stiffness of an elastic material and is a quantity used to characterize materials. It is defined as the ratio of the stress along an axis over the strain along that axis in the range of stress in which Hooke's law holds

Front 23

Define ultimate tensile strength (breaking stress)

Back 23

Ultimate tensile strength is the maximum stress that a material can withstand while being stretched or pulled before failing or breaking.

Front 24

Define elastic deformation

Back 24

Elastic behaviour when it regains its original shape

Front 25

Define plastic deformation

Back 25

Plastic behaviour when it is permanently distorted.

Front 26

Define weight

Back 26

Weight is the gravitational force on a body.

Front 27

Define density

Back 27

Density is defined as mass per unit volume.

Front 28

Define pressure

Back 28

Pressure is define as force per unit area.

Front 29

Define trilateration

Back 29

The method used for determining the position of the GPS receiver in a car is called trilateration.

Front 30

Define GPS

Back 30

GPE is the energy stored in an object (the work an object can do) by virtue of its position in a gravitational.

Front 31

State the principle conservation of energy

Back 31

It states that the total amount of energy in an isolated system remains constant over time

Front 32

State hooke's law

Back 32

Hooke's law states that the force needed to extend or compress a spring by some distance is proportional to that distance. That is, F=kX (as long as the elastic limit is not exceeded).