AS Physics Chapter 5

Work Done

When a force moves the point at which it acts in the direction of the force [moves impact point, scalar]

Work Done formula

Work done = Force * Displacement in the direction of the force

Displacement

Distance moved in a particular direction [vector]

One joule of work done

When 1 Newton of force moves its point of application 1 metre in the direction of the force

Condition for an object that can do work

The object must have energy

Law of conservation of energy

Energy cannot be created or destroyed, it can only be converted to one form or another

Efficiency

(Useful Energy / Total Energy) * 100

Energy

Ability to do work [scalar]

Power

Rate of energy conversion or usage, also known as the rate of work done

Watt

Unit of power and equivalent to working 1 joule per second

Deriving Equations Power

W = fx, divide both sides by time, Power = f * v

Potential Energy

Ability of an object to do work as a result of its position or shape

Gravitational potential energy

energy possessed by a mass as a result of its position in a gravitational field

Gravitational potential energy equation derivation

Work done = Fx = mg * h = mgh

Change in gravitational potential energy

ΔE = mgΔh

[Translational] Kinetic Energy

E [k] = 1/2mv²