Two particles A and B are projected simultaneously in a vertical plane as shown in figure. They collide at time t in air. Write down two necessary equations for collision to take place.

Answer

A, B, C

Explanation

(i) `x_A = x_B`
`:. 10 + (u_1 cos theta_1) t = 30 - (u_2 cos theta_2)t`
`:. (u_1 cos theta_1 + u_2 cos theta_2) t = 20`
(ii) `y_A = y_B`
`:. 10 + (u_1 sin theta_1)t - 1/2 g t^2= 20`
`+ (u^2 sin theta_2)t - 1/2 g t^2`
or `(u_1 sin theta_1 - u_2 sin theta_2)t = 10`.