A block of mass M is hanging over a smooth and light pulley through a light string. The other end of the strinig is pulled by a constant force F. The kinetic energy of the block increases by 20J n 1s.

A block of mass M is hanging over a smooth and light pulley through a

1.	A block of mass M is hanging over a smooth and light pulley through a light string. The other end of the strinig is pulled by a constant force F. The kinetic energy of the block increases by 20J n 1s.
Answer» the TENSION in the string is Mg The tension is the string is F The work DONE by the tension on the BLOCK is 20 J in the above 1s. the work done by the FORCE of gravity is -20J in the above 1s. Answer :B