Question

A mass of 2 kg is whirled in a horizontal circle by means of string at an initial speed of 5 r.p.m . keeping the radius constant the tension of string is doubled. the new speed is nearly______ ?

Answer 1

As the centrifugal force (radially outward) is given by

$m {w}^{2} r$

as by equilibrium Tension is equal to centrifugal force.

T= m(w*w)*r;

so when tension is doubled w becomes √2 times

√2*5 rpm is answer