3 motion & forces

kinematics

• velocity: rate of change of displacement

• acceleration: rate of change of velocity

• finding avg velocity from graph: (s/t)

equations of motion

conditions: constant acceleration, linear motion

1. s = ut + ½ at²

2. v = u + at

3. v² = u² + 2as

newton’s law of motion

1. object at rest will stay at rest, and object in motion will continue moving at constant velocity unless acted on by a resultant external force

2. rate of change of momentum is directly proportional to resultant force acting on the body & is in the same direction as Fr

• = Pf -Pi = m x change in v = density x A x v²

3. force exerted from first body on second body is equal in magnitude and opposite in direction as force exerted by second body on first body

• conditions:

  • equal in magnitude

  • opp in direction

  • same type of forces

  • same pair of objects

.

.