1. Key Areas covered Terminal velocity.
Velocity-time graph of a falling object when air resistance is taken into account, including the effect of changing surface the area of the falling object.

2. What we will do today: Revise what is meant by terminal velocity.
Draw a v-t graph for a parachutist jumping from a plane until they reach the ground.

3. Animation showing parachute journey

4. Terminal velocity
When an objects falls towards the Earth it has two vertical forces acting on it.

5. Terminal velocity
As the object falls towards Earth it’s velocity increases (due to the acceleration of gravity).
When the speed of an object increases so does the air resistance acting against it.
Eventually the two forces will balance out at the object will no longer accelerate (balanced forces = constant velocity).
This constant velocity is known as terminal velocity.

6. Graph of terminal velocity

7. Parachutes
When doing a parachute jump, the parachute is released to increase the surface area and as a result, the air resistance (friction) increases.
This slows the parachutist’s velocity allowing them to land safely.

8. Parachutists v-t graph