Free Falling

pandora

Just been thinking after I saw our current astronauts up above, us as we speak...
early this morning on the local news

thought I'd share

There Is Gravity in Space
Newton's law of gravity states that the gravitational force between any two objects in the universe is proportional to the mass of the objects and inversely proportional to the square of the distance (measured from their centers) between them. So if the distance between two objects doubles, the force between them is one fourth as much. But for the force to be exactly zero an object must be at an infinite distance. Hence there is a gravitational force everywhere in the universe from every mass in the universe. This force is negligible for distant objects but not zero.

Shuttle astronauts are orbiting only a few hundred miles above Earth's surface. This increases the astronauts distance from the Earth's center a few hundred miles out of about 4000 miles. So a 160 pound astronaut will still weigh about 140 pounds at a distance of 200 miles above Earth's surface. They are not weightless because there is less gravity up there.

Simple Free Fall Experiment
Poke a hole into the bottom of a paper cup. Covering the hole with your finger, fill it with water. Now hold it above your head and remove your finger. Water will drip out the hole. Drop the cup and watch it fall. While it is falling freely, the water does not drip out. Objects in free fall are weightless.



http://www.youtube.com/watch?v=VDu9z4SCTmc that looks way too much like fun!!

LikeAnOcean

I think you are confusing weight with mass.


You will always have the same mass. And unless you count air resistance as you are falling towards an object like the earth, your weight should be zero as you free fall. You will gain weight back when you hit the air resistance otherwise you would continue to excelerate indefinitely.

Astronauts orbiting the earth are in constant free fall, they are just moving so fast that the fall stays consistant with the curvature of the earth.

So.. without any resistance, you are weightless. If astronauts had 140 lbs of weight, they would be crashing into the earth... Maybe they weigh give or take a pound or two depending on their orbit speed, but they'd be in big trouble if they weighed 140 lbs.

EDIT: I see what you are saying.. Yes, you would weight 140 lbs at 200 miles above the earth if you weren't moving relative to the earth, say you were standing on a 200 mile tower.. although an astronaut should never have weight otherwise he's in big trouble.

This all raises the question for me, I wonder how much the speed of the earths rotation plays on our weight? Like, if the earth stopped rotating, would we gain weight?

pandora

LikeAnOcean wrote:

I think you are confusing weight with mass.


You will always have the same mass. And unless you count air resistance as you are falling towards an object like the earth, your weight should be zero as you free fall. You will gain weight back when you hit the air resistance otherwise you would continue to excelerate indefinitely.

Astronauts orbiting the earth are in constant free fall, they are just moving so fast that the fall stays consistant with the curvature of the earth.

So.. without any resistance, you are weightless. If astronauts had 140 lbs of weight, they would be crashing into the earth... Maybe they weigh give or take a pound or two depending on their orbit speed, but they'd be in big trouble if they weighed 140 lbs.

EDIT: I see what you are saying.. Yes, you would weight 140 lbs at 200 miles above the earth if you weren't moving relative to the earth, say you were standing on a 200 mile tower.. although an astonaut should never have weight otherwise he's in big trouble.

Sorry I took that from someone very smart...those aren't my words...I should have placed the link
here it is.... I am sorry for any confusion. My mind doesn't work like that I really don't get it
http://www.suite101.com/content/why-are ... ess-a22029
I liked the video I saw this am on the news and found the other on youtube
of them carrying on weightless
very cool I thought....
I love the heavens and those that know a lot about them.

Thank you for your input.... hope you liked the video too

arthurdent

pandora wrote:

Objects in free fall are weightless.

same reason why NASA's "Vomit Comet" works

pandora

arthurdent wrote:

pandora wrote:

Objects in free fall are weightless.

same reason why NASA's "Vomit Comet" works

Now that would be a cool screen name

I googled...thinking it was a free falling device to remove upchuck from the space shuttle

no I was wrong... it's the device that trains them in a near to weightless condition.

I live so close to Huntsville AL ...NASA.... a few hours drive.
I've always wanted to go, added to the bucket list.

Never to old to learn something new.

Thanks arthurdent