First slide

Gravitaional potential energy

Question

A particle of mass 10g is kept on the surface of a uniform sphere of mass 100kg and radius 10cm. Find the work to be done against the gravitational force between them to take the particle far away from the sphere is (G=6.67x 10^-11 Nm²kg^-2)

Moderate

A

6.67 × 10^-10J
B

6.67 x 10^-9 J
C

3.33 x 10^-10 J
D

13.34 x 10^-10 J

Solution

$\large P.E=\frac {GMm}{r}$
$\large U_i= \frac{{6.67 \times {{10}^{ - 11}} \times 10 \times {{10}^{ - 3}} \times 100}}{{0.1}}=-6.67\times 10^{-10}J$
U_f = 0[ As r is large]
$\large \therefore W=U_f-U_i=\left [ 0-(-6.67\times 10^{-10}) \right ]J=6.67\times 10^{-10}J$

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