Question

A grindstone has a moment of inertia of 6 kg m2. A constant torque is applied and the grindstone is
found to have a speed of 150 rpm. 10 seconds after starting from rest. Calculate the torque.​

Answer 1

Answer:

Torque = 3Pie

Torque = 9.426 Nm

Explanation:

The explanation is in the above attachment.

Answer 2

Given:

A grindstone has a moment of inertia of 6 kgm². A constant torque is applied and the grindstone is

found to have a speed of 150 rpm after 10 seconds after starting from rest.

To find:

The torque ?

Calculation:

Convert the rpm value into radians/second:

• 150 rpm = 150 × 2π/60 = 5π rad/sec.

• First,let's calculate the angular acceleration.

$\therefore \: \alpha = \dfrac{ \omega2 - \omega1}{t}$

$\implies\: \alpha = \dfrac{ 5\pi - 0}{10}$

$\implies\: \alpha = \dfrac{ \pi}{2} \: rad {s}^{ - 1}$

Now, torque will be :

$\implies \tau = I \times \alpha$

$\implies \tau = 6 \times \dfrac{\pi}{2}$

$\implies \tau = 3\pi \: Nm$

So, torque is 3π Nm.