Power = Work done / time
Work done = Force * Distance
= 300 N * 1.5 m = 450 J
Power = 450 / 0.75 = 600 Watts.
Answer:
Option D
Explanation:
The work done can be given by the mechanical energy used to do work, i.e., Kinetic energy and potential energy provided to do the work.
In all the cases, except option D, the energy provided to do the useful work is not zero and hence work done is not zero.
In option D, the box is being pulled with constant velocity, making the acceleration zero and thus Kinetic energy of the system is zero. Hence work done in this case is zero.
The net force on the hanging object is zero. If it were not zero, then the object would be accelerating in some direction.
