A skater rotates with her arms crossed at an angular speed of 8.0 rad/s and she has a moment of inertia of 100 kg/m2. She extends her arms, and her angular speed drops to 7.0 rad/s. What is her moment of inertia now

When her hands extends, her momen of inertia is .

Explanation:

Given that,

Initial angular speed,

Initial moment of inertia,

Final angular speed,

Initially, a skater rotates with her arms crossed and finally she extends her arms. The momentum remains conserved. Using the conservation of momentum as :

is final moment of inertia

So, when her hands extends, her momen of inertia is . Hence, this is the required solution.

answer: 31, 5556. 952 seconds