Force and motion Revise the following: Distance time graphs Velocity-time graphs Resultant force Terminal velocity Stopping distances

Distance time graph

Distance time graph

Distance time graph

Velocity-time graph

Velocity-time graph

Velocity-time graph

Velocity-time graph

Distance-time graph Velocity-time graph

Resultant forces There are usually several different forces acting on an object. The overall motion of the object will depend on the size and direction of all the forces. The motion of the object will depend on the resultant force. This is calculated by adding all the forces together, taking their direction into account. 50 N 30 N Resultant force on the crate = 50 N – 30 N = 20 N to the left

Resultant force Resultant force = mass x acceleration Object at the start Resultant force Effect on the object Stationary Zero Remain stationary Not zero Accelerate in the direction of the resultant force Moving Continue to move at same speed in same direction Resultant force = mass x acceleration newton (N) kilogram (kg) metre/second2 (m/s2)

Terminal velocity The faster a body moves through fluid, the greater the frictional force which acts on it. A body falling through a fluid will initially accelerate due to the force of gravity. Eventually the resultant force on the body will be zero and it will fall at its Terminal velocity

Stopping distance