Rotational Dynamics About a Fixed Axis: a String Is Wrapped

Multiple Choice

Rotational dynamics about a fixed axis: A string is wrapped around a pulley with a radius of 2.0 cm and no appreciable friction in its axle. The pulley is initially not turning. A constant force of 50 N is applied to the string, which does not slip, causing the pulley to rotate and the string to unwind. If the string unwinds 1.2 m in 4.9 s, what is the moment of inertia of the pulley?

A) 0.17 kg ∙ m²
B) 17 kg ∙ m²
C) 14 kg ∙ m²
D) 0.20 kg ∙ m²
E) 0.017 kg ∙ m²