AP EAMCET201921 Apr 2019Evening ShiftPhysicsRotational MotionActual
A wheel having moment of inertia 2 kg m 2 about its axis, rotates at 50 rpm about the same axis. The torque required to stop the wheel in one minute is
Options
- Aπ 10 Nm
- Bπ 18 Nm
- C- π 12 Nm
- D3 π 8 Nm
Correct answer
B. π 18 Nm
Step-by-step solution
Given, Moment of inertia of wheel I = 2   kg   m 2 Initial angular velocity ω 0 = 2 πN 60 = 2 π × 50 60 = 10 6 π   rad   s - 1 Final angular velocity ω = 0 Time required t = 1   min = 60   s Using first equation of motion- ω = ω 0 + α t ⇒     0 = 10 6 π + α   60 ⇒     α = - π 36   rad   s - 2 Torque required τ = I α = 2 × π 36 = π 18   Nm