First slide

Angular momentum

Question

A solid disc of mass 1 kg and radius 20 cm can rotate about an axis passing through its centre and perpendicular to its plane. A constant torque of 2 N-m is applied on the disc. Then its angular momentum after 5 sec is

Moderate

A

10 $k g - m^{2} / s$
B

8 $k g - m^{2} / s$
C

12 $k g - m^{2} / s$
D

6 $k g - m^{2} / s$

Solution

I = Moment of inertia $= \frac{1}{2} \times 1 \times {(0.2)}^{2} k g - m^{2} = 0.02 k g - m^{2}$
$∴ L_{f} - L_{i} = τ \times t \Rightarrow L_{f} - 0 = 2 \times 5 k g - m^{2} / s = 10 k g - m^{2} / s$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App