Q.) A block of mass M is hanging over a smooth and light pulley through a light string. The other end of the string is pulled by a constant force F. The kinetic energy of the block increases by 20 J in 1 s:
[A]the tension of the string is Mg
[B]the tension in the string is F.
[C]the work done by the tension on the block is 20 J in the above 1 s.
[D]the work done by the force of gravity is – 20 J in the above 1 s.
