TOPIC 1 - Freefall acceleration and terminal velocity

When there is no atmosphere, all objects falling from the same height reach the ground at...

the same time. This is because gravity is constant, so two objects will have the same acceleration.

Explanation of terminal velocity (before opening a parachute)

- WEIGHT stays the same for the whole journey but AIR RESISTANCE increases until it is the same as the WEIGHT.
- The forces are now balanced so the object falls with constant velocity.
- The object has reached terminal velocity.

Explanation of terminal velocity (after opening a parachute)

- WEIGHT stays the same for the whole journey but AIR RESISTANCE decreases until it is the same as the weight because there is more air resistance caused by a larger surface area of the parachute.
- The forces are now balanced so the object falls with a lower terminal velocity.

The terminal velocity of falling objects depends on their:

Shape and area.

Describe the forces acting on falling objects

- The force of GRAVITY pulls the object down towards the center of the Earth.
- The object experiences an upward force called AIR RESISTANCE (drag) as it falls through the air.