A bullet of mass 20 g moving with a velocity of 500 m/s, strikes a free and goes out from the other side with a velocity of `400 m//s.` Calculate the work done by the bullet in joule in passing through the tree.

Explanation

(a) Kinetic energy. It can be utilized for generatin hydroelectricity.
(b) As `K_i = (1)/(2) (10xx10^(-3)) (500)^2 J = 1250 J`
and `K_f= (1)/(2) (10 xx10Z^(-3)) (400)^2 J = 800 J,`
work done by the bullet, `W = K_i - K_j = 450J`