First slide

Rolling motion

Question

A disc of radius 2 m and mass 100 kg rolls on a horizontal floor. Its centre of mass has speed of 20 cm/s. How much work is needed to stop it?

Moderate

A

1 J
B

3 J
C

30 KJ
D

2 J

Solution

$Required work done = - (K_{f} - K_{i}) = 0 + K_{i} = K_{i} = \frac{1}{2} {Iω}^{2} + \frac{1}{2} {mv}^{2} = \frac{1}{2} (\frac{1}{2} {mR}^{2}) ω^{2} + \frac{1}{2} {mv}^{2} = \frac{3}{4} {mv}^{2} = \frac{3}{4} \times 100 \times {(20 \times 10^{- 2})}^{2} = 3 J$

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