Question

The earth $($mass$={10}^{24}kg)$ revolves around the Sun with an angular velocity $2\times {10}^{-7}rad{s}^{-1}$ in a circular orbit of radius $1.5\times {10}^{8}km$. Find the force exerted by the Sun on the earth $($in $\times {10}^{21}N)$.

Answer 1

Force exerted by the sun on the earth is same as the centripetal force required for the earth to revolve around the sun.
Hence, Force exerted by the sun $=mr{\omega }^2={10}^{24}\times 1.5\times {10}^{11}\times 4\times {10}^{-14}=6\times {10}^{21}N$