Two paper screens A and B are separated by 150m. A bullet pierces A and B. The hole in B in 15 cm below the hole in A. If the bullet is travelling horizontally at the time of hitting A, then the velocity of the bullet at A is: `(g=10ms^(-2))`

Options

A. `100 sqrt(3) m s^-1`
B. `200 sqrt(3) m s^-1`
C. `300 sqrt(3) m s^-1`
D. `500 sqrt(3) m s^-1`

Answer

D

Explanation

(d) Range `= 150 = ut and h = (15)/(100) = (1)/(2) xx gt^2`
or `t^2 = (2 xx 15)/(100 xx g) = (30)/(1000)` or `t =(sqrt(3))/(10)`
`u = (150)/(t) = (150 xx 10)/(sqrt(3)) = 500 sqrt(3) ms^-1`.