Physics Motion and Forces

scalar quantity

Only has magnitude (example: speed)

vector quantity

Has both magnitude and direction (example: velocity)

distance

The amount travelled

displacement

The shortest distance between the starting point and ending point.

acceleration

The rate of increase in speed.

deceleration

The rate of decrease in speed.

acceleration (formula)

Final velocity minus initial velocity divided by time.

speed (formula)

Distance traveled divided by time.

velocity (formula)

Displacement over time

Terminal velocity

When a object is falling and is no longer accelerating

weight

Mass times gravitational field strength

air resistance

The force that slows a object moving through air.

density

How much something weighs for it’s size

elasticity

How much an object can change shape and return to its original form.

extension

The extended length minus the original length.

spring constant

How much force it takes to stretch an object by a meter

Hooks law

The force equals the extension multiplied by the spring constant. (which is measured in newtons per metre)

elastic deformation

When a object deforms but is able to return to its original form.

inelastic deformation

When a object deforms but is unable to return to its original form.

elastic limit

The limit at where a object is able to return to its original form

resultant force

The force you are left with when subtracting the opposite forces from each other.

equilibrium

When the resultant force in all directions is zero.

Newton’s first law

An object does not accelerate if no resultant force is applied

Newton’s second law

If a non-zero resultant force acts on an object it will accelerate

The five ways acceleration can change the motion of an object

1) Start moving

2) Stop moving

3) Speed up

4) Slow down

5) change direction(speeds doesn’t change)

Inertia

How much force it takes to change an objects velocity.

Resultant force(formula)

force equals mass times acceleration

Moment

Is the turning effect of a force

Moment(formula)

Moment equals force times distance

Pivot

The point at which the force turns around.

Centre of gravity

The point where all the weight is expected to act from

Pressure (formula)

Force divided by area

Pressure

The amount of force per area