(II) A diver (such as the one shown in Fig. 8-28) can reduce her moment of inertia by a factor of about 3.5 when changing from the straight position to the tuck position. If she makes 2.0 rotations 1.5 s when in the tuck position, what is her angular speed (rev s) when in the straight position?

Step-by-step solution

Step 1 of 3</p>

CONCEPT

Consider the diver and platform as a system. There is no external torque acting on the system to change the angular velocity. So the angular momentum is conserved.

Therefore, by applying the conservation of angular momentum to the diver and platform system, we can calculate the final angular speed of the person.

Step 2 of 3 </p>

Letbe the moment of inertia of diver in the straight position.

Let be the moment of inertia of diver in the tuck position.

As the person initially makes 2.0 rotations in 1.5 s, initial angular velocity of the diver is given by the following expression

As the moment of inertia in tuck position is reduced by a factor of 3.5