A ballet dancer spins about a vertical axis at 120 rpm with arms outstretched. With her arms folded, the moment of inertia about the axis of rotation decreases by 40%. Calculate the new rate of rotation.

A ballet dancer spins about a vertical axis at 120 rpm with arms outst

1.	A ballet dancer spins about a vertical axis at 120 rpm with arms outstretched. With her arms folded, the moment of inertia about the axis of rotation decreases by 40%. Calculate the new rate of rotation.
Answer» <html><body><p></p>Solution :`n_(1)=120 rpm , n_(<a href="https://interviewquestions.tuteehub.com/tag/2-283658" style="font-weight:bold;" target="_blank" title="Click to know more about 2">2</a>)= ?"" I_(1)omega_(1)=I_(2)omega_(2)`<br/>Let `I_(1)=<a href="https://interviewquestions.tuteehub.com/tag/100-263808" style="font-weight:bold;" target="_blank" title="Click to know more about 100">100</a>` <a href="https://interviewquestions.tuteehub.com/tag/units-1438468" style="font-weight:bold;" target="_blank" title="Click to know more about UNITS">UNITS</a>, then `I_(2)=60` units <br/>`100xx120 = 60xx omega_(2) rArr omega_(2)=<a href="https://interviewquestions.tuteehub.com/tag/200-288914" style="font-weight:bold;" target="_blank" title="Click to know more about 200">200</a>` rpm.</body></html>