A bob of mass m is tied by a massless string whose other end portion is wound on a fly wheel (disc) of radius r and mass m. When released from the rest, the bob starts falling vertically. When it has covered a distance h, the angular speed of the wheel will be:
1
\(r \sqrt{\frac{3}{4 g h}}\)
2
\(\frac{1}{r} \sqrt{\frac{4 g h}{3}}\)
3
\(r \sqrt{\frac{3}{2 g h}}\)
4
\(\frac{1}{r} \sqrt{\frac{2 g h}{3}}\)