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
sin−145
sin−135
sin−143
sin−134
Given that
x = 36 t and 2y=96t−9⋅8t2
From the given equations, we have
Vx=dxdt=36 and vy=dydt=48−9⋅8t
At t=0,Vy=48
∴ V=Vx2+Vy2=60
This is shown in fig. (8).
From figure
sinθ=VyV=4860=45
or θ=sin−1 4/5