If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

## Class 11 Physics (India)

### Unit 11: Lesson 3

Angular kinematics

# Using rotational kinematic formulas

You might need: Calculator

## Problem

A fan initially rotates clockwise at 9, point, 0, start fraction, start text, r, a, d, end text, divided by, start text, s, end text, end fraction, but has a counterclockwise angular acceleration of 3, point, 0, start fraction, start text, r, a, d, end text, divided by, start text, s, end text, squared, end fraction and reaches a counterclockwise angular speed of 27, start fraction, start text, r, a, d, end text, divided by, start text, s, end text, end fraction.
How much time did this change in the angular velocity take?
Answer using a coordinate system where counterclockwise is positive.
Round answer to two significant digits.
start text, s, end text
Stuck?
Stuck?