# Conservation of Angular Momentum in Skater's Spin Rate Change

• Devin Longo
In summary, a figure skater initially spinning at a rate of 2 rev/s with her arms outstretched reduces her rotational inertia to 61% of its original value by drawing her arms into her chest. Using the conservation of angular momentum, her new rate of rotation can be calculated by setting the angular momentum before equal to the angular momentum after and solving for the unknown quantity.
Devin Longo

## Homework Statement

A figure skater is spinning at a rate of 2 rev/s with her arms outstretched. She then draws her arms into her chest, reducing her rotational inertia to 61% of its original value. What is her new rate of rotation?

?

## The Attempt at a Solution

w/2 = 1/sqrt(0.61)
w = 2.56 rev/s

This isn't correct according to the website, can someobody help me with a better equation and how to solve this one?

Thanks!

angular momentum before = angular momentum after

I still don't really understand

Angular momentum is conserved; it stays the same unless there is an external torque. So
angular momentum before = angular momentum after

You need to write the formula for angular momentum on both sides. Fill in the quantities you know and solve for the one you want to find.

## What is Skater Rate of Rotation?

Skater Rate of Rotation refers to the number of rotations a skater completes per minute while performing spins or jumps.

## How is Skater Rate of Rotation measured?

Skater Rate of Rotation is typically measured using high-speed video cameras that capture the number of rotations completed within a specific time frame.

## What factors affect Skater Rate of Rotation?

The primary factors that affect Skater Rate of Rotation include the skater's body position, speed, and the force exerted on the ice by the skater's blades.

## Why is Skater Rate of Rotation important?

Skater Rate of Rotation is an essential aspect of figure skating as it affects the quality and level of difficulty of a skater's performance. A higher rate of rotation can also lead to a higher score in competitions.

## Can Skater Rate of Rotation be improved?

Yes, Skater Rate of Rotation can be improved through proper technique, strength training, and practice. Skaters can also work with coaches to analyze their rotations and make adjustments to improve their Skater Rate of Rotation.

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