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 40J in 1s. State whether the following statements are true or false:
(a) The tension in the string is Mg
(b) The work done by the tension on the block is 40 J
(c) The tension in the string is F
(d) The work done by the force of gravity is 40J in the above 1s