Question

The earth (mass = $6 \times {10}^{24}$ kg) revolves around the sun with an angular velocity of $2 \times {10}^{-7} rad/s$ in a circular orbit of radius $1.5 \times {10}^8 km$. The force exerted by the sun on the earth, in newton, is

• A. $36 \times {10}^{21}$
• B. $27 \times {10}^{39}$
• C. zero
• D. $18 \times {10}^{25}$

Answer 1

Answer: (A)

$36 \times {10}^{21}$

Answer 2

Mass $(m)= 6 \times {10}^{24}\, kg;$
Angular velocity $(\omega) = 2 \times {10}^{-7} rad/s$ and
radius $(r) =1.5 \times {10}^{8} \, km = 1.5 \times {10}^{11} \, m$.
Force exerted on the earth $= mR {\omega}_2$
$= (6 \times {10}^{24}) \times ( 1.5 \times {10}^{11} ) \times (2 \times {10}^{-7})^2$
$= 36 \times {10}^{21 }\, N$.