Minimum Velocity for Pendulum Circle

A bullet of 10g, moving with velocity v, collides head-on with the stationary bob of a pendulum and recoils with velocity 100m∕s. The length of the pendulum is 0.5m and mass of the bob is 1‌kg. The minimum value of v .........m/s, so that the pendulum describes a circle.
(Assume, the string to be inextensible and g=10m∕s2)