Strength of Suns gravitational tug at earth orbit

[mythx]

I know this is simple math, but I'm too lazy to figure it out. If earth weren't orbiting the sun, but were somehow stationary with respect to the sun, how much would I weigh? I'm guessing we'd be crushed by the tug of the sun if we were at night time, and probably sucked off the planet if we were in daylight.

 

[MeteorWayne]

There would be almost no difference. Your weight is determined by your distance from the mass center of the earth. The gravitational effect of the sun is so small that it would not effect your weight more than an ounce or less.

And if you admit you're too lazy to figure it out for yourself, why should we waste our time calculating such a simple thing?

 

[drwayne]

Are you suggesting that the Earth is somehow "thumbtacked" into a stationary position?

The reason I ask this is that if the above is not true, then gravity acts on both the Earth, and the person,
leaving no net force.

Wayne

 

[drwayne]

By the way, in case you care, the value of "g" due to the sun at the Earth - Sun radius, call it gs is
approximately

6 x 10^-3 m/s^2

which is quite a bit less that the "g" we experience from the Earth, os I don't see to much flying or
skooshing going on, even for a fat tub of goo like me.

 

[mythx]

Yeah, I suppose for the sake of this question I am suggesting the earth be thumbtacked. I just did the math myself, and came up with the same number as you (5.9305 x 10^-3 actually). I guess distance makes a huge difference. What made me think about it was an article that mentioned the ISS is feeling about 90% of the gravity from earth that we feel at the surface. Next is to calculate how far from the sun you'd be to experience 1g.

Thanks

 

[mythx]

Looks like you'd have to be just about 3,000,000 KM from the sun to experience 1g.

 

[Solifugae]

Looks like you'd have to be just about 3,000,000 KM from the sun to experience 1g.

If you were also accelerating towards the sun at 1g would the effect on a person in a rocket be canceled out at that point.

 

[aphh]

If you were also accelerating towards the sun at 1g would the effect on a person in a rocket be canceled out at that point.

The net force is the resultant of all vectors of forces acting on a body, so yes, the forces would cancel each other, if two opposite 1g forces or accelerations were acting on a body.

 

[drwayne]

Note also that if you have a system of objects that all experience a common force, for example, gravity,
then there is no net force that is generated within the elements of the system. (Images of free fall in KC-135's
leaps to mind as a good example, though Einstein like elevators)

Wayne

 

[aphh]

Actually there is a tiny bit of force between the elements of a system, that would be the gravity between the elements themselves. However, this gravity between a KC-135 and a astronaut in training in a free fall is so small that it can be ignored in every calculations.

I don't know any application where the gravity between the elements of a system in a vicinity of a humongous mass (=Earth) is even mentioned, albeit in theory it is there. In electrophysics gravity between charged particles is completely ignored and the only force considered would be the electrostatic force, albeit the particles have a mass and therefore would also have a gravity between them.