A bomb initially at rest at a height of 40 m above the ground suddenly explodes into two identical fragments. One of them starts moving vertically downwards with an initial speed of 10 m/s. If acceleration due to gravity is 10 `m//s^2`, the separation between the fragments, 2 seconds after the explosion is

Explanation

Initial relative velocity `u_(rel)=10-(-10)=20m/s`
Relative acceleration `a_(rel)=g-g=0`
After t = 2 sec, relative separation
`S_(rel)=u_(rel)t+(1)/(2)a_(rel)t^(2)=(20xx2)+0=40 m`