Question

What is the binding energy of earth-sun system neglecting the effect of other planets and satellites? (Mass of earth $M_{e}=6 \times 10^{24} kg$, mass of the sun $M_{s}=2 \times 10^{30} kg ^{-2}$ Distance between earth sum $=1.5 \times 10^{11} m$ ) Assume circular orbit of earth around sun

• A. $8.8\times {10}^{10}\mathrm{}\mathrm{J}$
• B. $8.8\times {10}^3\mathrm{}\mathrm{J}$
• C. $5.2\times {10}^{33}\mathrm{}\mathrm{J}$
• D. $2.6\times {10}^{33}\mathrm{}\mathrm{J}$

Answer 1

Answer: (D)

Binding energy of the system $=\frac{- G M_{e} M_{s}}{2 r}$
$=\frac{-6.6 \times 10^{-11} \times 6 \times 10^{24} \times 2 \times 10^{30}}{2 \times 1.5 \times 10^{11}}$
$=-2.6 \times 10^{33} J$
$| BE |=2.6 \times 10^{33} J$