Question

Give one example in which force is applied but no gain in energy.

Answer 1

Hey ya !!!!

When planets move in orbit around the sun, the planets move with centripetal force but it does not do any work. The planets move tangentially to their orbits and form a right angle to the centripetal force. So by W=FScosΘ 

When planets move in orbit around the sun, the planets move with centripetal force but it does not do any work. The planets move tangentially to their orbits and form a right angle to the centripetal force. So by W=FScosΘ Θ=90 and cos 90 is 0. So work becomes 0.