Jumat, 15 Januari 2010

WORK, ENERGY AND POWER


WORK, ENERGY AND POWER


Imagine a porter carrying a load on his head. Is he doing any work? Yes, one would say! He would be paid for carrying that load from one place to another. But in terms of Physics he is not doing any work! Again, imagine a man pushing a wall? Do you think he is doing any work? Well, his muscles are contracting and expanding. He may even be sweating. But in Physics, we would say he is not doing any work!

If the porter is carrying a very heavy load for a long distance, we would say he has lot of energy. By this, we mean that he has lot of stamina. If a car can run at a very high speed, we say it is very powerful. So, we relate power to speed. However, it means something different in Physics. Let us understand what is meant by work, power and energy in Physics.

Work