Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

In any case, if the force and power is constant , does velocity also need to be constant? If no, can you tell me a case. Further can this be extended for non-rigid bodies.

share|cite|improve this question

If the velocity is constant, there is no acceleration so there is no net force.

So, consider an example where an external force acts on an object that also experiences an oppositely directed frictional force proportional to the speed of the object.

There will be a speed where the two forces cancel and the object will no longer accelerate.

The power delivered by the external force is then constant but rather than increasing the KE of the object, the energy is converted into heat and the power is the rate of that conversion.

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.