Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.

Suppose there were no Earth to pull us back and we're hanging in the solar system. Assuming no other force of gravity from other bodies, what would be the $g$ from the Sun?

share|improve this question
add comment

1 Answer

up vote 6 down vote accepted

You can get this from Newton's law of gravitation: the acceleration due to gravity is then $$ g=\frac Fm =G\frac{mM_\odot }{mr^2}=\frac{GM_\odot}{r^2}, $$ which comes out to about 5 mm/s$^2$. This is of course the orbital acceleration of Earth.

share|improve this answer
    
Would that orbital acceleration be the speed that one object travels along the orbital? How fast an object( typical human) travels along that orbital if $ g= 5 mm/s^2$? –  laovultai Jan 27 '13 at 11:59
    
You're confusing speed and acceleration. (!). The orbital speed of Earth is about 30 km/s. Anything at Earth's position with an orbital speed smaller than that would go much closer to the Sun; below 3 km/s you're likely to crash into it. –  Emilio Pisanty Jan 29 '13 at 12:44
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.