# An object with a mass of # 3 kg# is traveling in a circular path of a radius of #3 m#. If the object's angular velocity changes from # 4 Hz# to # 7 Hz# in # 8 s#, what torque was applied to the object?

##### 1 Answer

Nov 11, 2017

#### Explanation:

Torque is rate of change of angular momentum.

#= (I2pi(f_f - f_i))/t#

#= (mr^2 2pi(f_f - f_i))/t#

#= ("3 kg × (3 m)"^2 × 2 π (7 - 4) "Hz")/"8 s" = "63.6 Nm"#