A block of mass 2 kg 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 = 40 N. The kinetic energy of the particle increases 40 J in a given interval of time. Then, `(g = 10 m//s^(2))`
A. tension in the string is 40 N
B. displacement of the block in the given interval of time is 2 m
C. work done by gravity is `-20 J`
D. work done by tension is 80 J
