drhex

2012-Jun-08, 10:57 AM

While watching the Venus transit, I was thinking "What would it take to move the entire planet Venus so it could break away from the straight path across the Sun, would even the entire power of the Sun be enough?"

So, more formally: If the entire power output of the Sun (some 4e26 Watts, I think) was put to work accelerating the planet Venus instead of producing photons, neutrinos and helium, what acceleration could be provided?

Intuitively, Newton's formula F = m*a seems to be the one I need. "a" is the quantity I am seeking, "m" is the mass of Venus which is easy to look up. So, if I only had "F" I could compute "a". "F" is the force, in Newtons. But I don't have any Newtons to do the job, instead I have some number of Watts.

Watts = Joules / second.

Joules = Newton*meters.

So Watts is Newtons*meters/second

So, if I could divide those Watts with a velocity (meters/second) I'd have the required Newtons to put into the F = m*a (or rather a = F/m) formula. But what velocity would that be?

I've gotten the units mixed up somehow, can you please help?

So, more formally: If the entire power output of the Sun (some 4e26 Watts, I think) was put to work accelerating the planet Venus instead of producing photons, neutrinos and helium, what acceleration could be provided?

Intuitively, Newton's formula F = m*a seems to be the one I need. "a" is the quantity I am seeking, "m" is the mass of Venus which is easy to look up. So, if I only had "F" I could compute "a". "F" is the force, in Newtons. But I don't have any Newtons to do the job, instead I have some number of Watts.

Watts = Joules / second.

Joules = Newton*meters.

So Watts is Newtons*meters/second

So, if I could divide those Watts with a velocity (meters/second) I'd have the required Newtons to put into the F = m*a (or rather a = F/m) formula. But what velocity would that be?

I've gotten the units mixed up somehow, can you please help?