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Work done on three different masses

the formula for work

In this movie, you see three masses all with identical forces acting on them. The force on each object remains active until it reaches the end of the distance shown. Even though the smaller masses accelerate more than the larger masses, the same amount of work is done on each object. As a result of the same amount of work being done on each, the kinetic energy (KE) of each object is the same. (remember that energy is just stored work) Notice on the graph that each object reaches the same KE just at different times. You should also notice that just because the KEs are equal doesn't mean that the velocities are equal.

Power is defined as the time rate of doing work, or the rate of using energy. Even though the same amount of work is done on each object, the power rating of the work being done is different.The power rating of the least massive block is much higher than the power rating of the other blocks because the time in which the work is done is so much shorter. Remember the formula for Power is work done divided by the change in time.


This simulation is assuming that there is no friction of any kind.