Question

At high altitude , a body explodes at rest into two equal fragments with one fragment receiving horizontal velocity of `10 m//s`. Time taken by the two radius vectors connecting of explosion to fragments to make `90^(@)` is
A. `10 s`
B. `4 s`
C. `2 s`
D. `1 s`

Answer 1

Correct Answer - C
`theta + theta = 90^(@) rArr theta = 45^(@)`
`tan theta = (x)/(y) = (10 t)/((1)/(2) g t^(2)) = (2)/(t)`
`tan 45^(@) = (2)/(t) rArr t = 2s`