First slide

Gravitational force and laws

Question

Three identical point masses, each of mass 1 kg lie in the x-y plane at points (0, 0), (0, 0.2m) and (0.2m, 0). The net gravitational force on the mass at the origin is

Moderate

A

$1 .67 \times 10^{- 9} (\hat{i} + \hat{j}) N$
B

$3.34 \times 10^{- 10} (\hat{i} + \hat{j}) N$
C

$1 .67 \times 10^{- 9} (\hat{i} - \hat{j}) N$
D

$3.34 \times 10^{- 10} (\hat{i} - \hat{j}) N$

Solution

Let particle A lies at origin, particles B and C on y and X-axis respectively
${\vec{F}}_{AC} = \frac{{Gm}_{A} m_{B}}{r_{AB}^{2}} \hat{i} = \frac{6 .67 \times 10^{- 11} \times 1 \times 1}{(0 .2)^{2}} \hat{i} = 1 .67 \times 10^{- 9} \hat{i} N$
Similarly ${\vec{F}}_{AB} = 1 .67 \times 10^{- 9} \hat{j} N$
$∴$ Net force on Particle A
$\vec{F} = {\vec{F}}_{A C} + {\vec{F}}_{A B} = 1 .67 \times 10^{- 9} (\hat{i} + \hat{j}) N$

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