# Terminal Velocity

## Key Stage 4

### Meaning

Terminal velocity is the velocity a falling object reaches when the forces of drag and weight on that object are balanced.

Terminal velocity depends on:

Terminal velocity is the maximum velocity an object will reach when falling due to gravity.
Terminal velocity occurs because air resistance increases with speed until the air resistance is balanced with the weight, at which point the object will stop accelerating.
 At the start the penguin is not yet moving and the only force acting on the penguin is its weight. So the resultant force is large which means the acceleration will be large. As the penguin starts to accelerate its small velocity results in an air resistance that acts against its weight. So the resultant force is less than it was so the acceleration will be less. As the penguin accelerates more its hight velocity results in more air resistance that acts against its weight. So the resultant force is even smaller than it was so the acceleration will be smaller. Once the penguin is moving fast enough the velocity results in an air resistance that is as large as the weight. Resultant Force = 0N So there is no resultant force and so the acceleration will be zero. The penguin has reached terminal velocity.

### References

#### AQA

Terminal velocity, page 141, GCSE Physics; Student Book, Collins, AQA
Terminal velocity, page 211, GCSE Combined Science; The Revision Guide, CGP, AQA
Terminal velocity, page 63, GCSE Physics; The Revision Guide, CGP, AQA
Terminal velocity, pages 146-147, GCSE Physics; Third Edition, Oxford University Press, AQA
Terminal velocity, pages 156-7, GCSE Physics, Hodder, AQA
Terminal velocity, pages 159-161, GCSE Combined Science Trilogy; Physics, CGP, AQA
Terminal velocity, pages 190-192, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA
Terminal velocity, pages 234-5, GCSE Combined Science Trilogy 2, Hodder, AQA

#### OCR

Terminal velocity, page 29, Gateway GCSE Physics; The Revision Guide, CGP, OCR
Terminal velocity, pages 70, Gateway GCSE Physics, Oxford, OCR