A bomb is released from an aeroplane flying at a speed of `720 km//h` in the horizontal direction `8000 m` above the gorund. At what horizontal distance from the initial position of areoplane it strikes the ground.

Explanation

`O` to `B` :
`u = 720 xx (5)/(18) = 200 m//s`
`y = h = (1)/(2) g t^(2)`
`8000 = (1)/(2) xx 10 t^(2) rArr t = 40 s`
`x = ut = 200 xx 40 = 8000 m`
OR
Equation of trajectory
`y = (g x^(2))/(2 u^(2))` (Remember this formula)
`8000 = (10 x^(2))/(2 xx (200)^(2))`
`x^(2) = (8000)^(2)`
`x = 8000 m`