on page 108, question 2.34: A mass m whirls around on a string which passes through a ring, ngelect gravity. initially the mass is distance r0 from the centre and is revolving at angular velocity w0. the string is pulled with constant velocity V starting at t=0 so that the radial distance to the mass decreases. obtain a differential equation for w(t). here what i did: v'=w0r0 r(t)=r0+Vt v'=w(t)*r(t) w(t)r(t)=w0r0 but from the text this isnt correct, can someone help me here?