A Mechanic Is Examining the Wheel of a Bicycle to Adjust

question 24

Multiple Choice

A mechanic is examining the wheel of a bicycle to adjust the brake. With the bicycle off the ground, he manually rotates the wheel until it reaches an angular speed of 12.0 rad/s and then allows it to coast to a stop. If the wheel has a moment of inertia of 0.100 kg∙m², and the wheel slows to a stop in 160 s, what is the magnitude of the retarding torque?

• A) 1.00 Nm
• B) 0.00750 Nm
• C) 0.0787Nm
• D) 1.33 Nm
• E) 1.67 Nm