A figure skater spins with arms extended. When she pulls her arms in, what happe

₹0.0

Question: A figure skater spins with arms extended. When she pulls her arms in, what happens to her angular velocity?

Options:

Correct Answer: Increases

Solution:

By conservation of angular momentum, pulling arms in decreases moment of inertia, thus increasing angular velocity.

A figure skater spins with arms extended. When she pulls her arms in, what happens to her angular velocity?

A figure skater spins with arms extended. When she pulls her arms in, what happens to her angular velocity?

Correct Answer: Angular velocity increases.

Step 1: Understand that the figure skater is spinning. This means she has angular momentum, which is a measure of how much motion she has while spinning.
Step 2: Know that angular momentum is conserved. This means that unless an external force acts on the skater, her total angular momentum will stay the same.
Step 3: Recognize that the skater has a moment of inertia, which is a measure of how spread out her mass is from the center of her spin. When her arms are extended, her moment of inertia is larger.
Step 4: When the skater pulls her arms in, her moment of inertia decreases because her mass is now closer to the center of her spin.
Step 5: Since angular momentum is conserved, if the moment of inertia decreases, the angular velocity (how fast she spins) must increase to keep the angular momentum the same.
Step 6: Conclude that when the skater pulls her arms in, her angular velocity increases.

Conservation of Angular Momentum – The principle that the total angular momentum of a closed system remains constant if no external torques act on it.
Moment of Inertia – A measure of an object's resistance to changes in its rotation, which depends on the mass distribution relative to the axis of rotation.
Angular Velocity – The rate of rotation of an object around an axis, typically measured in radians per second.