Chapter 10, Problem 19PE

Unreasonable Results

A gymnast doing a forward flip lands on the mat and exerts a 500-

$\text{N}\cdot \text{m}$ torque to slow and then reverse her angular velocity. Her initial angular velocity is 10.0 rad/s, and her moment of inertia is $0.050\text{kg}\cdot {\text{m}}^2$. (a) What time is required for her to exactly reverse her spin? (b) What is unreasonable about the result? (c) Which premises are unreasonable or inconsistent?