Question

The earth $(Me=6\times {10}^{24}kg)$ is revolving round the sun in an orbit of radius $(1.5\times {10}^8)$ km with angular velocity of $(2\times {10}^{-7})$ rad/s. The force (in newton) exerted on the earth by the sun will be

• A. $36\times {10}^{21}$
• B. $16\times {10}^{24}$
• C. $25\times {10}^{16}$
• D. zero

Answer 1

Answer: (A)

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

Force exerted by the sun is gravitational force which is equal to centrifugal force.

$F=mr{w}^2$

Given: $m=6\times {10}^{24}kgr=1.5\times {10}^{11}mw=2\times {10}^{-7}rad/s$

$⟹F=36\times {10}^{21}N$