Find the rotational kinetic energy of a ring of mass 9 kg and radius 3 m rotating with 240 rpm about an axis passing through its centre and perependicualr to its plane.

Find the rotational kinetic energy of a ring of mass 9 kg and radius 3

1.	Find the rotational kinetic energy of a ring of mass 9 kg and radius 3 m rotating with 240 rpm about an axis passing through its centre and perependicualr to its plane.
Answer» <html><body><p></p>Solution :The rotational <a href="https://interviewquestions.tuteehub.com/tag/kinetic-533291" style="font-weight:bold;" target="_blank" title="Click to know more about KINETIC">KINETIC</a> <a href="https://interviewquestions.tuteehub.com/tag/energy-15288" style="font-weight:bold;" target="_blank" title="Click to know more about ENERGY">ENERGY</a> is, `<a href="https://interviewquestions.tuteehub.com/tag/ke-527890" style="font-weight:bold;" target="_blank" title="Click to know more about KE">KE</a>=(1)/(2) <a href="https://interviewquestions.tuteehub.com/tag/iomega-2133375" style="font-weight:bold;" target="_blank" title="Click to know more about IOMEGA">IOMEGA</a>^(2)` <br/> the moment of inertin of the ring is `I=MR^(2)` <br/> `I=9xx3^(2)=9xx9=81 kg m^(2)` <br/>the angular speed of the ring is, <br/> `omega=240 pm =(240xx2pi)/(60) "rad" s^(-1)` <br/> `KE=(1)/(2)xx81xx((240xx2pi)/(60))=(1)/(2)xx81xx(8pi)^(2)` <br/> `KE=(1)/(2)xx81xx64xx(pi)^(2)=2592xx(pi)^(2)` <br/> `KE ~~25920 J "" :. (pi)^(2)=10` <br/> `KE~~25.9250 <a href="https://interviewquestions.tuteehub.com/tag/kj-1063034" style="font-weight:bold;" target="_blank" title="Click to know more about KJ">KJ</a>`</body></html>