First slide

Law of conservation of angular momentum

Question

Keeping the mass of earth as constant, if its radius is reduced to 1/4th of its initial value, then the period of revolution of earth about its own axis and passing through the centre, in hours, is (Assume earth to be a solid sphere and its initial period of rotation as 24 hrs).

Easy

A

1.5
B

12
C

3
D

6

Solution

M = constant,
$\large {R_2} = \frac{{{R_1}}}{4},\,\,{T_1} = 24hr\,\,{T_2} = ?$

$\large {I_1}{w_1} = {I_2}{w_2}$

$\large \frac{2}{5}MR_1^2.\frac{{2\pi }}{{{T_1}}} = \frac{2}{5}MR_2^2.\frac{{2\pi }}{{{T_2}}}$

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