Question

Two bodies of masses $10 \, kg$ and $100 \, kg$ are separated by a distance of $2 \, m$ . The gravitational potential at the mid-point of the line joining the two bodies is:

• A. $-7.3\times 10^{- 7 \, }J / k g$
• B. $-7.3\times 10^{- 8 \, }J / k g$
• C. $-7.3\times 10^{- 9 \, }J / k g$
• D. $-7.3\times 10^{- 6 \, }J / k g$

Answer 1

Answer: (C)

As we know, gravitational potential
$V=\frac{- G M}{R}$
Gravitational potential at mid point,
$=-\frac{G \times 10}{1}-\frac{G \times 100}{1}=-110 \, G$
$=- \, 110\times 6.67\times 10^{- 11} \, J \, k g^{- 1}$
$=-7.3\times 10^{- 9}\text{ J} \, \text{kg}^{- 1}$