A fan that was rotating at a speed of 450 revolutions per second for 5 minutes had its speed setting turned down to 240 revolutions per second after 5.5 minutes. What is the angular acceleration over this period of time?

Question

Quizplus · Accepted Answer

The formula for angular acceleration (α) is: α = Δω/Δt Where: Δω is the change in angular velocity (expressed in revolutions per second - rev/s) Δt is the change in time (expressed in seconds) Δω = ω₂ - ω₁ Δt = t₂ - t₁ Convert units: 5.5 minutes = 330 seconds 5 minutes = 300 seconds α = (240 rev/sec - 450 rev/s) / (330s - 300s) α = - 210 rev/sec / 30s α = - 7 rev/sec² Since the speed was turned down, the sign is negative.

A Fan That Was Rotating at a Speed of 450