Physics Q: If you throw a baseball from space shuttle

[tranceport]

At 200 miles above the earth, how long will it take for a baseball to reach the surface. How fast will it travel in mph at it's peak?

 

[sao123]

Originally posted by: tranceport
At 200 miles above the earth, how long will it take for a baseball to reach the surface. How fast will it travel in mph at it's peak?

without some long calculations, i cannot say for certain how long it will take to fall to the surface... however... since orbital speed is the peak speed (you must decelerate to deorbit), the orbital velocity of approximately 17,300 @ 200 miles altitude will be your peak velocity.

if you are thinking "terminal velocity"...the measured terminal velocity of a baseball is 92mph. However during deorbiting, terminal velocity will be exceeded because the initial velocity of the object was >>>>>> the terminal velocity.

 

[Kirby]

Ask kylebisme. He's a whiz at math and physics.

 

[dennilfloss]

Originally posted by: PieIsAwesome
Objects in orbit are "falling"

Yup. An orbit is just a slow fall.

 

[Jeff7]

Originally posted by: dennilfloss

Originally posted by: PieIsAwesome
Objects in orbit are "falling"

Yup. An orbit is just a slow fall.

Or rather, it's a fall toward a surface that, because of your speed relative to a spherical object, keeps moving away from you.

 

[Fayd]

Originally posted by: lyssword

Originally posted by: Mojoed

Originally posted by: lyssword
thx guys

Did you win?

Yes, I showed this thread and convinced them that you guys are legit geeks/physics people :laugh:

how's that possible, when a large portion of this forum adamantly maintains that .999... != 1?

 

[Ika]

Originally posted by: Fayd

Originally posted by: lyssword

Originally posted by: Mojoed

Originally posted by: lyssword
thx guys

Did you win?

Yes, I showed this thread and convinced them that you guys are legit geeks/physics people :laugh:

how's that possible, when a large portion of this forum adamantly maintains that .999... != 1?

Only the idiots.

 

[Argo]

The baseball will burn down and the only thing reaching earth will be ashes.

 

[lyssword]

Originally posted by: Argo
The baseball will burn down and the only thing reaching earth will be ashes.

What if it was made out of titanium?

 

[sandorski]

Alright, this is bugging me: What causes Objects to burn up when entering Earth's Atmosphere?

I always thought it had to do with a high velocity and the friction of hitting the atmosphere. So what am I missing here?(aka 100mph is *not* a high velocity)

 

[GodlessAstronomer]

Originally posted by: sandorski
Alright, this is bugging me: What causes Objects to burn up when entering Earth's Atmosphere?

I always thought it had to do with a high velocity and the friction of hitting the atmosphere. So what am I missing here?(aka 100mph is *not* a high velocity)

The space station is zipping around the Earth at around 17,000mph, so even though you only gave the ball 100mph velocity towards the Earth, it's still going to be traveling through the atmosphere very, very fast.

 

[sandorski]

Originally posted by: GodlessAstronomer

Originally posted by: sandorski
Alright, this is bugging me: What causes Objects to burn up when entering Earth's Atmosphere?

I always thought it had to do with a high velocity and the friction of hitting the atmosphere. So what am I missing here?(aka 100mph is *not* a high velocity)

The space station is zipping around the Earth at around 17,000mph, so even though you only gave the ball 100mph velocity towards the Earth, it's still going to be traveling through the atmosphere very, very fast.

Ok. If it was thrown from a Stationary platform, would it then not burn up?(aka only traveling at 100mph)

 

[PlasmaBomb]

Originally posted by: lyssword

Originally posted by: Argo
The baseball will burn down and the only thing reaching earth will be ashes.

What if it was made out of titanium?

The ashes would be titanium dioxide...

 

[PlasmaBomb]

Originally posted by: sandorski

Originally posted by: GodlessAstronomer

Originally posted by: sandorski
Alright, this is bugging me: What causes Objects to burn up when entering Earth's Atmosphere?

I always thought it had to do with a high velocity and the friction of hitting the atmosphere. So what am I missing here?(aka 100mph is *not* a high velocity)

The space station is zipping around the Earth at around 17,000mph, so even though you only gave the ball 100mph velocity towards the Earth, it's still going to be traveling through the atmosphere very, very fast.

Ok. If it was thrown from a Stationary platform, would it then not burn up?(aka only traveling at 100mph)

You could do some maths to work it out...

It depends how high the platform is... but at 200 miles up it would have a decent length of time to accelerate (since 95% of the Earth's atmosphere lies below 50,000 ft) before its terminal speed became 92mph.

The excess kinetic energy will be converted by friction to mainly heat. So yes it would burn up.

 

[Squisher]

Originally posted by: PlasmaBomb

Originally posted by: lyssword

Originally posted by: Argo
The baseball will burn down and the only thing reaching earth will be ashes.

What if it was made out of titanium?

The ashes would be titanium dioxide...

Diamond?

 

[Jeff7]

Originally posted by: Squisher

Originally posted by: PlasmaBomb

Originally posted by: lyssword

Originally posted by: Argo
The baseball will burn down and the only thing reaching earth will be ashes.

What if it was made out of titanium?

The ashes would be titanium dioxide...

Diamond?

 

[arcenite]

Originally posted by: Jeff7

Originally posted by: Squisher

Originally posted by: PlasmaBomb

Originally posted by: lyssword

Originally posted by: Argo
The baseball will burn down and the only thing reaching earth will be ashes.

What if it was made out of titanium?

The ashes would be titanium dioxide...

Diamond?

:laugh:

 

[artikk]

Originally posted by: Jeff7

Originally posted by: Squisher

Originally posted by: PlasmaBomb

Originally posted by: lyssword

Originally posted by: Argo
The baseball will burn down and the only thing reaching earth will be ashes.

What if it was made out of titanium?

The ashes would be titanium dioxide...

Diamond?

 

[IronWing]

Originally posted by: artikk

Originally posted by: Jeff7

Originally posted by: Squisher

Originally posted by: PlasmaBomb

Originally posted by: lyssword

Originally posted by: Argo
The baseball will burn down and the only thing reaching earth will be ashes.

What if it was made out of titanium?

The ashes would be titanium dioxide...

Diamond?

That there was almost a baseball joke, son.

 

[Jeff7]

I am sooo lost right now.

 

[feralkid]

Originally posted by: sao123
The deorbit delta V is quite calculatable.

Depending on the orbit, it may or may not be able to deorbit the baseball.
depending on the orbit (ecliptic vs circular) path, a deorbit delta V could range from 22 m/s (50mph) to 137 m/s (300 mph).

this of course need a lot of unexpressed information for your problem:
altitude
entry altitude
entry trajectory
semimajor axis
eccentricity
argument of perigee
perigee altitude
apogee altitude
entry true anomaly
entry velocity
impulse-to-entry time



/what do i win?

Scorn,

"Calculatable" is not a word.

 

[sao123]

Originally posted by: feralkid

Originally posted by: sao123
The deorbit delta V is quite calculatable.

Depending on the orbit, it may or may not be able to deorbit the baseball.
depending on the orbit (ecliptic vs circular) path, a deorbit delta V could range from 22 m/s (50mph) to 137 m/s (300 mph).

this of course need a lot of unexpressed information for your problem:
altitude
entry altitude
entry trajectory
semimajor axis
eccentricity
argument of perigee
perigee altitude
apogee altitude
entry true anomaly
entry velocity
impulse-to-entry time



/what do i win?

Scorn,

"Calculatable" is not a word.

those who have time for math and physics...do not have time for spelling and grammar.
calculable... happy?

 

[jman19]

Originally posted by: nkgreen
Ask kylebisme. He's a whiz at math and physics.

:thumbsup:

 

[Bignate603]

Originally posted by: GodlessAstronomer

Originally posted by: KillerCharlie
That depends on what orbit the shuttle is in - if it's in the same orbit as the space station, I think it would fall back without being thrown - if I recall correctly, the space station is in a degrading orbit and has to be boosted periodically.

If memory serves me the space station is in a stable orbit but there is still a thin atmosphere up there. The friction with the atmosphere causes the shuttle to slow over time and this will cause the orbit to decay without boosters.

Everything is in a degrading orbit, it's just how fast the orbit is decaying. Like you said there is enough atmosphere near the space station that the degradation is noticeable and they designed it with the ability to give it a push to higher orbit as needed to counteract the degradation.

There is no defined line where the atmosphere stops though and all things in orbit experience some slowing. There's some small amount of molecules that an orbiting body will hit, even quite far out. It's pretty easy to see though at higher orbits there will be less molecules, to the point of being RIDICULOUSLY small amounts of slowing. At a high enough orbit the amount of molecules an object would run into can be so low this could take ridiculous amounts of time, so that from our standpoint it's effectively a non-decaying orbit. If it will take 100,000 years for something to fall out of the sky we don't really worry too much about it.

 

[Bignate603]

Originally posted by: PlasmaBomb

Originally posted by: sandorski

Originally posted by: GodlessAstronomer

Originally posted by: sandorski
Alright, this is bugging me: What causes Objects to burn up when entering Earth's Atmosphere?

I always thought it had to do with a high velocity and the friction of hitting the atmosphere. So what am I missing here?(aka 100mph is *not* a high velocity)

The space station is zipping around the Earth at around 17,000mph, so even though you only gave the ball 100mph velocity towards the Earth, it's still going to be traveling through the atmosphere very, very fast.

Ok. If it was thrown from a Stationary platform, would it then not burn up?(aka only traveling at 100mph)

You could do some maths to work it out...

It depends how high the platform is... but at 200 miles up it would have a decent length of time to accelerate (since 95% of the Earth's atmosphere lies below 50,000 ft) before its terminal speed became 92mph.

The excess kinetic energy will be converted by friction to mainly heat. So yes it would burn up.

With the gravity and aerodynamic forces changing as the ball fell it would be a pretty interesting problem to solve.