Table of Contents
IGCSE Coordinated Science: Power
Relate (without calculation) power to work done and time taken, using appropriate examples.
Remember in the last unit we talked about “work”? What is work again? Work is the product of the force produced on a point and the distance the point moves in the direction of the force.
Work is independent of time. There is no time component in work. For example, if we’re pushing a box from point A to point B, how long we push it will NOT affect the work done.
If you really want to measure how time is linked with work, we will have to introduce the concept of power – and for the moment, without any formulas.
Power is a very straightforward concept. It’s simply a measure of the rate at which work is done.
Consider the example of moving an object between Point A and B, and we repeat this twice. Assuming both trials have equivalent forces produced on the object/point, and the distance from point A to B is the same, but the time taken for Trial 1 to move the object was 3 seconds and 5 seconds in Trial 2, which trial had a higher power?
As the work done on both trials is the same, we can focus on the “rate at which work was done”. As power is the rate at which work is done, Trial 1 only took 3 seconds compared to 5 seconds, so it is doing work at a higher rate, and thus at a higher power as compared to Trial 2.
Recall and use the equation P = E / t in simple systems.
Mathematically, power can be calculated using the formula:
P = Power
W= Work Done
T= Time taken
Power is measured in Watts.
