Question

A wheel accelerates uniformly from rest to 2000 r.p.m. in 20 seconds. What is its angular acceleration?

(a) 10.475 rad/s^2

(b) 12 rad/s^2

(c) 14 rad/s^2

(d) 15 rad/s^2

The question was posed to me in examination.

I'd like to ask this question from Acceleration of a Particle along a Circular Path in chapter Kinematics & Kinetics of Motion of Machine Kinematics

Answer 1

Right option is (a) 10.475 rad/s^2

The explanation is: Solution. Given : N0 = 0 or ω = 0 ; N = 2000 r.p.m. or ω = 2π × 2000/60 = 209.5 rad/s ; t = 20s

Angular acceleration

Let α = Angular acceleration in rad/s^2

We know that

ω = ω0 + α.t

or 209.5 = 0 + α × 20

or α = 209.5 / 20 = 10.475 rad/s^2