Linear kinetics - external forces

What’s kinetics?

A study of the cause of motion.

What’s force?

The physical interaction with an object and its surroundings.

They have a magnitude, direction and point of application.

Law of inertia

A body will continue in a state of rest or motion in a straight line unless acted upon by an external force.

Law of acceleration

If we apply a force it will cause an acceleration of the object proportional to the force applied.

Force = mass x acceleration

Law of action - reaction

For every action there is an equal and opposite reaction

What’s gravity?

It constantly acts downwards, pulling things to centre of the earth at 9.81 m/s²

Everything will accelerate at the same rate.

What’s ground reaction force?

The force the ground exerts on a body in contact with it.

What’s friction?

The resistance that one surface or object encounters when moving over another.

What’s air resistance?

A type of friction between air and another material.

What are impact forces?

A large force that occurs when two objects collide.

What are elastic forces?

A force that returns an object to its original shape after it has been deformed.

Occurs when an external force is applied to an elastic object.