Unit 1 As Physics Definitions

Front 1

Vector

Back 1

Measurement with magnitude and direction

Hint 1

Force, acceleration, velocity, displacement

Front 2

Scalar

Back 2

Measurement with magnitude but no direction

Hint 2

Time, mass, speed, distance, energy

Front 3

Gravitational force

Back 3

W=mg, g=9.81

Front 4

Newton ' s first law

Back 4

A body at rest or travelling at a constant velocity will remain in that state unless acted upon by a resultant force.

When resultant force is zero the body is in equilibrium

Front 5

Newtons second law of motion

Back 5

The acceleration of a body is directly porportional to and in the direction of the resultant force applied on it.

F=ma

Front 6

Newtons third law

Back 6

If body A exerts a force on body B then body B will exert an equal force of the same type in the opposite direction on body A

Front 7

Equations of motion

Back 7

Constant acceleration

Front 8

First law of thermodynamics

Back 8

Energy cannot be created or destroyed. It is only transfered from one form to another

Hint 8

Energy conservation

Front 9

Work done

Back 9

Work done by a force is the energy transfered by the force on a moving body.

If the force is constant:

W=fd (distance moved in the direction of the force)

Front 10

Density

Back 10

Mass per unit volume

Front 11

Hookes law

Back 11

Provided the limit of proportionality is not exceeded, the extension of an elastic material is directly porportional to the applied force (tension/compression)

F=kx

Front 12

Elastic strain energy

Back 12

Energy stored in an object under deformation.

Average force used

Area under force strain graph

E=0.5fx=0.5kx^2

Front 13

Young Modulus

Back 13

Measure of the stiffness of a material provided the limit of proportionality is not exceeded.

E=stress/strain

Front 14

Stress

Back 14

Stress=F/A

Front 15

Strain

Back 15

Strain= extension/original length

Front 16

Limit of proportionality

Back 16

Point of stress strain or force extension graph where graph stops being linear.

Hookes law no longer obeyed

Front 17

Elastic limit

Back 17

Max load where bday regains it's original size

Front 18

Yield point

Back 18

Marked increase in extension for a small increase in stress.

Plastic deformation occurs

Front 19

Hysterisis

Back 19

Force extension graph for loading and unloading are different.

Energy lost as heat

Front 20

Creep

Back 20

When a material keeps extending over several minute even though a constant stress/force is applied.

Front 21

Ultimate tensile strength

Back 21

Stress required to break a material under tension

Front 22

Strong

Back 22

A large force/stress required to break it

Front 23

Elastic behaviour

Back 23

Object returns to its original shape/size when the force is removed.