This topic covers the concept of force and free body diagrams. It includes Newtons laws of motion and the concept of linear momentum.
Force
A force on a body is a push or pull acting on the body from some external body. Unit: N
Newtons 3rd law
If body A exerts and force on body B then body B will exert an equal yet opposite force on A.
Formula for resultant force.
Σ F = ma
The mass of a body x its acceleration.
Momentum
The momentum of an object is its mass multiplied by its velocity (P= mv) Unit: Kg m s ^-1
Newtons 2nd law in terms of momentum.
The resultant force is proportional to the rate of change of momentum.
The principle of conservation of momentum
The vector sum of momentum remains constant provided there is no external force.
Elastic collision
A collision in which there is no change in total kinetic energy.
Inelastic collision
A collision in which kinetic energy is lost.