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## High school physics

### Unit 7: Lesson 6

Angular momentum and angular impulse

# Angular impulse calculations

You might need: Calculator

## Problem

A boat's propeller has a rotational inertia of 4, point, 0, start text, k, g, end text, dot, start text, m, end text, squared. After a constant clockwise torque is applied for 12, start text, s, end text, the propeller's angular speed changes from a clockwise 6, point, 0, start fraction, start text, r, a, d, end text, divided by, start text, s, end text, end fraction to a clockwise 18, start fraction, start text, r, a, d, end text, divided by, start text, s, end text, end fraction.
What was the torque applied to the propeller?
Answer using a coordinate system where counterclockwise is positive.
start text, N, end text, dot, start text, m, end text
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