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)

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 $=mR{\omega }^2$
$=\left(6\times 10^{24}\right)\times \left(1.5\times 10^{11}\right)\times {\left(2\times 10^{-7}\right)}^2$
$=36\times 10^{21}N$