Momentum and energy

• The momentum of a body is mass multiplied by velocity.
• Impulse is the change in momentum and can also be found by multiplying force by time.
• The conservation of momentum states that the total momentum before equals the total momentum after.
• The conservation of momentum equation is m1 u1 + m2 u2 = m1 v1 + m2 v2.
• When two bodies collide they exert an impulse on each other of equal magnitude but in opposite directions.
• The kinetic energy of a particle is 1/2 m v^2.
• The gravitational potential energy of a particle is m g h.
• When calculating GPE, choose a fixed level where GPE equals zero.
• Work done is force in the direction of motion multiplied by distance moved.
• Work done against gravity = m g h.
• When no external forces besides gravity do work on a particle during its motion, the total energy of the particle remains constant.
• The change in total energy of a particle equals the work done on it.
• Power is the rate of doing work and equals force multiplied by velocity.