physics term 1

Time

s, scalar

Distance

m, scalar

Displacement

m, vector

Speed

m/s, scalar

Velocity

m/s, vector

Acceleration

m/s², vector

Force

N, vector

Volume

L, scalar

km/h → m/s

divide by 3.6

m/s → km/h

multiply by 3.6

Newton’s First Law

Object stays at rest or constant motion unless acted on by an external force (inertia)

Inertia

Resistance to change in motion (more mass = more inertia)

Balanced forces

Equal forces → no change in motion

Unbalanced forces

Unequal forces → causes acceleration (speed up, slow down, change direction)

Newton’s Second Law

F = ma (greater force = more acceleration, less mass = more acceleration)

Newton’s Third Law

For every action force there is an equal and opposite reaction force (on different objects)

Kinetic energy examples

• motion

• light

• heat

• sound

Potential energy examples

• elastic

• gravitational

• chemical

• static

Law of Conservation of Energy

energy can’t be created or destroyed; only transformed or transferred

Wasted energy

• (mainly) friction

• air resistance

Efficiency formula

efficiency = (useful energy / wasted energy) x 100

Sankey diagram