Browse Questions

# Two bodies of mass $10^2 kg$ and $10^3kg$ are lying 1m apart. The gravitational potential at mid point of line joining them is

$(a)\;0 \quad (b)\;-1.47\;J/kg \quad (c)\;1.47 \;J/kg \quad (d)\;1.47 \times 10^{-7} J/kg$

Potential at center = Potential due to mass 1 + Potential due to mass 2
$\qquad= \large\frac{-Gm_1}{r_1}-\frac{Gm_2}{r_2}$
$\qquad= -6.67 \times 10 ^{-11} \bigg[ \large\frac{10^2}{5}+\frac{10^3}{5}\bigg]$
$\qquad= 1.47 \times 10^{-7} J/kg$
Hence d is the correct answer

edited Feb 17, 2014 by meena.p