Physics Q: If you throw a baseball from space shuttle

[bret]

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:

i just googled it

 

[waggy]

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?

and still refuse to admit the plane takes off!

Originally posted by: ironwing
It's no use, the Cubs will still lose.

ohh so true..but fuck you =(

 

[sandorski]

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.

I've always liked Math, but always sucked at it. I'm like the guy in Office Space. Always doing some little error to make the results way off. :laugh:

 

[TridenT]

Originally posted by: ironwing
It's no use, the Cubs will still lose.

:laugh: Win.

 

[EarthwormJim]

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)

What do you mean by a Stationary platform? Something in a geosynchronous orbit or a very very tall tower?

Either way, the ball is still traveling at a very high velocity. If it's angular velocity is matching the earth's, but it's 26k miles up, it's going to have a very fast tangential velocity. It'll hit the earth's atmosphere going very fast (faster than 100mph.)

 

[sandorski]

Originally posted by: EarthwormJim

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)

What do you mean by a Stationary platform? Something in a geosynchronous orbit or a very very tall tower?

Either way, the ball is still traveling at a very high velocity. If it's angular velocity is matching the earth's, but it's 26k miles up, it's going to have a very fast tangential velocity. It'll hit the earth's atmosphere going very fast (faster than 100mph.)

I suppose it would be interesting to know at what Velocity and object hitting the Atmosphere creates enough friction to cause enough heat to start burning. Basically I'm wondering if anything could fall to Earth without burning(outside of some extremely high temp resistant material). I suppose that I'm stumbling over Terminal Velocity here and not grasping just how much Force the Earth's Gravity is able to accelerate a falling object without TV to slow it down....and then the sudden braking caused by TV is what really causes the burning(too much Friction too suddenly).

I really should have just Studied this shit. :laugh:

 

[silverpig]

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?

Those calculations don't apply.

For both types of initial orbits, the de-orbit maneuver consists of a tangential impulsive
?V applied opposite to the velocity vector of the initial orbit at the maneuver orbital location.

The baseball is not thrown in this direction.

 

[silverpig]

I think this thread is full of fail. I'm not willing to do the calcs, but I'm pretty sure you'll just send it into an elliptical orbit, and, neglecting air friction as all good physics problems do, it will maintain this orbit.

 

[silverpig]

See solution here

It's not necessarily the same, but firing rocket engines from a circular orbit leads to an elliptical orbit. Orbits aren't that hard to achieve once you're in one.

 

[silverpig]

With that out of the way, let's take a look at orbital dynamics. You can't actually throw anything (or yourself) out of orbit--all you can do is throw an object, or move yourself, from one orbit to another. If you want to go to a higher orbit, you need to increase your speed in the direction you're traveling. If you want to go to a lower orbit, you need to decrease your speed. Just trying to thrust straight up or down won't work too well: Thrusting down, for instance, will lower you temporarily, but now you're going too fast to stay in that lower orbit, and you'll end up oscillating back above your original orbit. As science fiction author Larry Niven put it, "East takes you out, out takes you west, west takes you in, and in takes you east."

Source

So the answer is no, it won't re-enter.

 

[sao123]

Originally posted by: silverpig

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?

Those calculations don't apply.

For both types of initial orbits, the de-orbit maneuver consists of a tangential impulsive
?V applied opposite to the velocity vector of the initial orbit at the maneuver orbital location.

The baseball is not thrown in this direction.

deceleration is the only direction it makes sense to throw it in... which direction exactly would you throw it in?

 

[silverpig]

Originally posted by: sao123

deceleration is the only direction it makes sense to throw it in... which direction exactly would you throw it in?

The one the OP specified?

Topic Title: Physics Q: If you throw a baseball from space shuttle
Topic Summary: toward earth

ie, "down"

 

[DrPizza]

My intuition tells me that silverpig's reasoning is correct. Let's ignore that there actually are frictional forces at the space shuttle's altitude, which seems to be in the spirit of the hypothetical question being asked. Otherwise, the question is pointless - the orbit will degrade toward earth.

But, given that the shuttle is moving around 17,000 miles per hour, a 100 mph throw, perpendicular to its path, is only going to change the velocity vector slightly. The orbit will become more elliptical, but the Earth won't be in the path of that orbit.

So, it will go into a different, more elliptical orbit. Sorry, OP, you lose.

 

[Gothgar]

hahaha, win thread is win

good times

 

[Matthiasa]

It doesn't matter what way its thrown really. It is still in low earth orbit where the effects of the atmosphere is not negligible, which is why satellites have thrusters to keep in orbit.

 

[Goosemaster]

REFUTATION

 

[sao123]

Originally posted by: silverpig

Originally posted by: sao123

deceleration is the only direction it makes sense to throw it in... which direction exactly would you throw it in?

The one the OP specified?

Topic Title: Physics Q: If you throw a baseball from space shuttle
Topic Summary: toward earth

ie, "down"

my point was... a deceleration throw would go a LOT further toward getting the baseball back to earth, than a perpendicular one. As I stated earlier, its possible to deorbit with a throw of 50mph in the proper eliptical orbit, but as the orbit becomes more circular it could take up to 300 mph.

 

[IronWing]

Originally posted by: Goosemaster
REFUTATION

I bet that gets more funnier the more drunk/stoned/high/wasted/smashed/shipfaced/plastered/gassed/ripped you get.

 

[lyssword]

Hmm, alright I'll disclose this new information
I guess that's why it's called rocket science