Calculate the work done in increasing the angular velocity of a wheel of moment of inertia 200 kg m_2 from 20 rev/s to 40 rev/s.

Calculate the work done in increasing the angular velocity of a wheel

1.	Calculate the work done in increasing the angular velocity of a wheel of moment of inertia 200 kg m_2 from 20 rev/s to 40 rev/s.
Answer» Solution :Initial ANGULAR velocity `=omega_(0) = 2pi n_(0) = 2pi XX 20` rad/s FINAL angular velocity `=omega = 2pi n = 2pi xx 40` rad/s Moment of intertia `=I =200 kg m^(2)` Work done `W = 1//2 l omega^(2) -1//2 I omega_(0)^(2)` `=1/2 xx 200 [(80 pi)^(2)-(40 pi)^(2)] = 4.73 xx 10^(4)` J