A shell is fired vertically upward with a speed of 60 m/s. When at its maximum height it explodes into large number of fragments. Assume that the fragments fly in every possible direction and all of them have same initial speed of 25 m/s [Take `g = 10 m//s^(2)`]
(a) Prove that after the explosion all the fragments will lie on an expanding sphere. What will be speed of the centre of the sphere thus formed – one second after explosion ?
(b) Find the radius of the above mentioned sphere at the instant the bottom of the sphere touches the ground.

Answer

(a) 10 m/s
(b) 100 m