Q.

A string of length L is fixed at one end and carries a mass of M at the other end. The mass makes (3π) rotations per second about the vertical axis passing through end of the string as shown. The tension in the string is __________ ML.          [2025]


Ans.

(36)

T cos θ = mg                 ... (i)

T sin θ = Mω2R           ... (ii)

Using equation (ii)

T sin θ = Mω2(L sin θ)

T=Mω2L=M(3π×2π)2L=36 ML