Question

A diver performs a $4.5$ somersault. During his dive he uses the tuck position so that he will have:

• A. Larger angular momentum
• B. Smaller angular momentum
• C. Larger rotational rate
• D. Smaller rotational rate
• E. Longer time in the air

Answer 1

Answer: (C)

Larger rotational rate

We know angular momentum $\overrightarrow{L}=I\overrightarrow{\omega }=\Sigma m{r}^2\overrightarrow{\omega }$

when a diver performs somersault his angular momentum remains constant because he behaves as an isolated system, so in above formula $\overrightarrow{L}$ and mass $m$ are constants now when he uses the tuck position he decreases the $r$ (distance from axis of rotation) and due to that $\overrightarrow{\omega }$ (angular velocity) increases or we can say larger rotational rate.