Two fly wheels A and B are mounted side by side with frictionless bearings on a common shaft. Their moments of inertia about the shaft are 5 . 0 kg m 2 and 20 . 0 kg m 2 respectively. Wheel A is made to rotate at 10 revolution per second. Wheel B, initially stationary, is now coupled to A with the help of a clutch. The rotation speed of the wheels will become

Step-by-step solution

When wheel B, initially stationary is coupled to A with the help of a clutch, both will have a common angular velocity and let that be ω . Since there is no external torque, angular momentum will be conserved. From conservation of angular momentum, I ω = I 1 ω 1 + I 2 ω 2 ⇒ I ω = 5 × 10 + 20 × 0 ⇒ I ω = 50 ⇒ 5 + 20 ω = 50 ⇒ ω = 50 5 + 20 ⇒ ω = 2   rps