Question

A woman whose mass is 70 kg stands at the rim of a horizontal turntable that has a moment of inertia 300 kg m^2 and radius of 2 m. the system is initially at rest and is free to rotate about frictionless vertical axle through the center of the turntable. The woman begins to walk clockwise around the rim at a speed 1.5 m/s relative to the earth. In what direction and with what angular speed does the turntable rotate?
Need a solution

Answer 1

let the angular velocity of the table be w.so, conserving angular momentum,

initial momentum = final momentum.

so,

0=300*w-1.5*2*70

or w=0.7 rad/s (anit-clockwise)