Angular Acceleration of a washing machine

Question

A washing machine slows from 75 rad/s to 25 rad/s while rotating through an angle of 450 radians. What is the angular acceleration of the washing machine?

Answer 1

ω² - ω₀² = 2φε; ε = (ω² - ω₀²)/(2φ) = (25² - 75²)/(2·450) = - 5.56 rad/s².