# A particle of mass m, initially at rest, is acted upon by a variable force F for a brief interval of time T. It begins to move with a velocity u after the force stops acting. F is shown in the graph as a function of time. The curve is a semicircle.

Q: A particle of mass m, initially at rest, is acted upon by a variable force F for a brief interval of time T. It begins to move with a velocity u after the force stops acting. F is shown in the graph as a function of time. The curve is a semicircle.

(a) $u = \frac{\pi F_0^2}{2 m}$

(b) $u = \frac{\pi T^2}{8 m}$

(c) $u = \frac{\pi F_0 T}{4 m}$

(d) $u = \frac{ F_0 T}{2 m}$

Ans: (c)