The initial speed of a bullet fired from a rifle is 630 ~m / s . The rifle is fired at the centre of a target 700 ~m away at the same level as the target. How far above the centre of the target ?

Step-by-step solution

Let ' t ' be the time taken by the bullet to hit the target. aligned & 700 ~m =630 ~ms ⁻¹ t & t= 700 ~m 630 ~ms ⁻¹ = 10 9 sec aligned For vertical motion, Here, u=0 aligned & h= 1 2 g t^2 &= 1 2 10 ( 10 9 )^2 aligned = 500 81 ~m =6.1 ~m Therefore, the rifle must be aimed 6.1 ~m above the centre of the target to hit the target.