Question

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))`

Answer 1

Equation of motion in x- direction, `100 = v xx t`
`rArr t = (100)/(v)`…(i)
In y - direction,
`0.1 = 1//2 xx 10 xx t^2` …(ii)
`0.1 = 1//2 xx 10 xx (100//v)^2`
From Eqs (i) and (ii), we get
`u = 700 m s^-1`.