A spherical ball of mass `M` moving with initial velocity `V` collides elastically with another ball of mass `M`, which is fixed at one end of `L` shaped rigid massless frame as shown in Fig. (a). The `L` shaped frame contains another mass `M` connected at the other end.

How soon will the frame come to the orientation shown in Fig. (b) after collision?

Options

A. `(7piL)/(4v)`
B. `(piL)/(2v)`
C. `(7piL)/(8v)`
D. `(piL)/(v)`

Explanation

Use conservation of linear and angular momemtum along with conservation of kinetic energy. (elastic collision)