Question

The flywheel of a steam engine has a radius of gyration of 1 m and mass 2500 kg. The starting torque of the steam engine is 1500 N-m and may be assumed constant. Determine : Angular acceleration of the flywheel.

(a) 0.6 rad/s^2

(b) 0.8 rad/s^2

(c) 0.10 rad/s^2

(d) none of the mentioned

I got this question in an interview for internship.

My question is from Numericals On Kinetics Of Motion and Loss of Kinetic Energy topic in chapter Kinematics & Kinetics of Motion of Machine Kinematics

Answer 1

Right option is (b) 0.8 rad/s^2

The explanation is: Given : k = 1 m ; m = 2500 kg ; T = 1500 N-m

 Angular acceleration of the flywheel

Let α = Angular acceleration of the flywheel.

We know that mass moment of inertia of the flywheel,

I=m.k^2 = 2500×12 = 2500 kg-m^2

We also know that torque ( T ),

1500 = I .α = 2500 × α

or α = 1500 / 2500 = 0.6 rad/s^2