The equations of motion of a projectile are given by x = 36 t metre and 2y=96t−9⋅8t2 metre. The angle of projection is

Given thatx = 36 t and 2y=96t−9⋅8t2From the given equations, we haveVx=dxdt=36 and vy=dydt=48−9⋅8tAt     t=0,Vy=48∴ V=Vx2+Vy2=60This is shown in fig. (8).From figuresin⁡θ=VyV=4860=45or      θ=sin−1 4/5