What torque would have to be applied to a rod with a length of #4 m# and a mass of #3 kg# to change its horizontal spin by a frequency of #3 Hz# over #2 s#?
The torque applied to the rod is 37.68 Newton-metre.
Torque is defined as the product of moment of inertia and angular acceleration
Moment of inertia of rod is
Now the torque becomes
Substituting the given values we get,