A constant force F1=10√3N applied at an angle 30∘ with horizontal on body (m=5 kg) at rest for 8 second. In this time interval, body moves from position A to B. To move from position B to A, another constant force F2=20 N is applied on body . If work done by this force is 960 J, then find the angle at which the force is acting on the body with horizontal.