Physics Puzzle

[onlinebiker]

You are an astronaut on the International Space Station. You are making an EVA in order to change a battery. When you finish up - you decide to be a litterbug and give the old battery a careful shove z straight "down" - that is - towards the planet's center mass.

What will be the path of the batteity - in relation to your point of view?

[polymath257]

Depends on how fast you can push that battery. What is the delta v and at what point of the orbit are you giving it? The answer also depends, partly, on your respective masses to determine the energy given to both you and the battery.

At first, the batter will move away from you, apparently in the downward direction, After a while (about a quarter of the orbit, depending on the eccentricity of the original orbit), it will appear to turn around and come back up. It will cross slightly in front of you and go higher at about the half, orbit stage. There is a possibility of collision at the crossing point.

At about 3/4 orbit, it will start to 'fall' back down and hit you just at the point in the orbit that you pushed it away.


Reasoning: the forward velocity stays the same, but you are adding a 'vertical' component to the velocity in the downward direction. That also adds an upward vertical component to your own velocity. The new orbit for the battery is originally slightly inside of your new orbit. By Kepler's law, the inside orbit will move slightly ahead of the outer orbit while both will be elliptical (unless you can *really* push*). But that means that the battery will be slightly ahead when the orbits cross on the other side. But then, the situation is reverse, with the battery going slightly slower in its orbit and you slightly faster in yours. The two effects don't exactly cancel (depending on the energy division), but it is closer than the first crossing.

[brewer]

Atmosphere friction will eventually curve the path as density increases. Apparently solar wind will also have an effect. I looked at NASA. 

That's about as much as I can contribute.

Edit: Partial ninja. Now I just sound stupid.

[onlinebiker]

Two incomplete.

[Peebothuhlu]

You are an astronaut on the International Space Station. You are making an EVA in order to change a battery. When you finish up - you decide to be a litterbug and give the old battery a careful shove z straight "down" - that is - towards the planet's center mass.

What will be the path of the batteity - in relation to your point of view?

It will appear to accelerate 'forwards' in relation to the station's current orbit.

Scott Manly has a Youtube vid on if an Astronaut can throw something hard enough for it to de-orbit.

Also... playing Kerbal Space Program and trying to keep near Kerbin space Kessler free is also good experience.



Not at work.

[John 6IX Breezy]

Just sraight down unless/until it burns up in the atmosphere?

[zebo-the-fat]

Just sraight down unless/until it burns up in the atmosphere?

"Straight down" isn't straight down, it will still have the orbital velocity. To send it straight down you would need to accelerate it in the oposite direction to your orbit at the same speed as your orbit (aprox 7.66 km/s) this will make appear stationary with respect to the Earth and it will just fall. (This is why rockets don't go straight up, they also travel horizontaly to gain the orbital speed.)
(Check out some of Scott Manley's youtube videos)

[John 6IX Breezy]

Right, but the question was in relation to my point of view not the Earth's.

[onlinebiker]

Just sraight down unless/until it burns up in the atmosphere?

No.

[John 6IX Breezy]

No.

In the event that it doesn't burn, I would predict that it would appear to get caught in the Earth's spin until hitting the ground. Like throwing a stick in a river.