A partical A is projected with an initial velocity of $60 m/s$ at an angle $30 ^{\circ}$ to horizontal . At the same time a second particle B is projected in the opposite direction with initial speed of $50 m/s$ from a point at a distance of $100 m$ from A. If the particle collide in mid air. find the angle of projection $\alpha$ of particle B.$(g=10 m/s^2)$

Question

$$(a)\;\sin ^{-1} \frac{1}{2} \quad (b)\;\sin ^{-1} \frac{3}{4} \quad (c)\;\sin ^{-1} \frac{1}{3}\quad(d)\;\sin ^{-1} \frac{3}{5}$$