A man stands holding a weight in each hand and with his arms outstretched on a frictionless platform which is rotating at a speed of 1 revolution per sec. In ths position the total rotational intertia of the man, the weights and the platform is `6kgm^(2)`. If by drawing in his arms, the man decreases the rotational inertia of the system by `2kg m^(2)`, calcualte the resulting speed of the platform and the increase in kinetic energy. How do you account for the increase of kinetic energy?

Options

A. 2 rps
B. 4 rps
C. 3 rps
D. 6 rps

Answer

C

Explanation

`I_(1)omega_(1)=I_(2)omega_(2)`