TOPIC :GRAVITATION
Number of questions are 173, Select_Question:

QUESTION
Q1) The earth ( mass=6 × 1024kg) revolves around the sun with an angular velocity 2 × 10-7 rad/sec in a circular orbit of radius=1.5 × 1011km. The force exerted by sun on earth in newton is ...[ AFMC 1997, 1999]




SOLUTION

Force exerted by sun on the earth is centripetal force.
Centripetal force=mω2r
m=6 × 1024kg
ω=2 × 10-7 rad/sec
r=1.5 × 1011km
substituting values in above equation we get
Centripetal force=6 × 1024 × (2 × 10-7)2 × 1.5 × 1011
=36 × 1021
Answer: (a)