Question

if a man is suddenly Falls from second floor of building then what is its kinetic energy

Answer 1

its kinetic energy is half of the his body's mass times in square of velocity he is falling down from the floor

Answer 2

Kinetic energy can be calculated by 1/2mv^2
m =mass
v = velocity.
IF it falls from second floor it depends mass of man and with how much velocity the man has fallen.
Hope it helps.