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 is:

• A. $zero$
• B. $18\times {10}^{20}$ N
• C. $27\times {10}^{30}$ N
• D. $3.6\times {10}^{22}$ N

Answer 1

The correct option is D $3.6\times {10}^{22}$ N

As per question $\omega =2\ast {10}^{7}rad/s,r=1.5\ast {10}^{8}km=1.5\ast {10}^{11}m$
And force exerted is given by
$F=\frac{m(rw{)}^2}{2}=\frac{6\ast {10}^{24}\ast (2\ast {10}^7\ast 1.5\ast {10}^{11})}{2}=3.6\ast {10}^{22}N$