Laws of motion

Every object remains at rest

Every object remains at rest or in uniform motion unless compelled to change by a net external force. This law defines inertia as the natural tendency

Inertia is the property that resists

Inertia is the property that resists changes in motion, and mass is the measure of inertia. Greater mass means greater inertia - it's harder to push a

The rate of change of momentum

The rate of change of momentum equals the net applied force (F = ma for constant mass, or F = Δp/Δt in general). Acceleration is directly proportional

Momentum (p) is the product

Momentum (p) is the product of mass and velocity (p = mv). It's a vector quantity that represents 'mass in motion' and determines the impact an object

For every action

For every action, there is an equal and opposite reaction. Forces always occur in pairs acting on different objects simultaneously (F₁₂ = -F₂₁).