Physics 2 Unit 3

Work = Force x (distance in the direction of the force)

Work is measured in joules

Power = Energy ➗ time

Gravitational potential energy is the energy stored in an object because of its position I'm a gravitational field

Ep = m x g x h

• Ep = change in gravitational potential energy /J
• m = mass /kg
• g = gravitational field strength per kilogram / N/Kg
• h = change in height in metres

Ek = 1/2 x m x v" (squared)

• Ek = kinetic energy
• m = mass
• v = speed

P = m x v

• P = momentum kgm/s
• m = mass
• v = velocity

The total momentum before the interaction is equal to the total momentum afterwards - providing that no external forces act on them

Crumple zones in cars are designed to fold in a collision. This increases the impact time and so reduced the force on the car and people in it