Question

A ring of radius 1m and mass 1 kg is rotating with an angular acceleration of $5\frac{rad}{s^2}$ about an axis passing through its centre and perpendicular to its plane. What will be the magnitude of tangential acceleration of any of its small point mass?

• A. $5m/s^2$
• B. $1m/s^2$
• C. $\sqrt{6}m/s^2$
• D. $6m/s^2$

Answer 1

The correct option is A $5m/s^2$

As you already know that angular and tangential acceleration of rigid body in rotation are related by, $a_t=r.\alpha$ ...(1)

Here all elementary masses are at the same distance from its axis of rotation.

Thus all must have same tangential acceleration. Putting all the corresponding values in (1), we get,
$a_t=1\times 5=5\frac{m}{s^2}$