An object with a mass of # 2 kg# is traveling in a circular path of a radius of #4 m#. If the object's angular velocity changes from # 2 Hz# to # 7 Hz# in # 2 s#, what torque was applied to the object?

1 Answer
Dec 22, 2016

Answer:

The torque is #=502.7m#

Explanation:

The torque is the rate of change of angular momentum.

#tau=(dL)/dt=(d(Iomega))/dt=I(domega)/dt#

The moment of inertia is #I=mr^2#

#I=2*4^2=32kgm^2#

The rate of change of angular velocity is

#(domega)/dt=(7-2)/2*2pi#

#=5pi rads^(-2)#

So the torque is #tau=32*5pi Nm=502.7Nm#