1. At 80,000 feet, how fast do you have to be traveling to produce enough friction to melt titanium?

If anyone can answer that or tell me how to figure it out, it would be very helpful.

Thank you.  2.

3. Originally Posted by Jshep08
At 80,000 feet, how fast do you have to be traveling to produce enough friction to melt titanium?

If anyone can answer that or tell me how to figure it out, it would be very helpful.

Thank you.
You see, melting point of titanium is 1668 °C. That itself is quite high.
Also, you should mention what amount of titanium are you calculating for, from 24 Km ??

:-D  4. Note: Post your question in their respective section, like this should have been in Physics  5.   6. Sorry i haven't got any idea as i never went 80000 feet height   7. By friction do you mean drag from air?
Be sure to use SI units:
Force= 0.5*air density*drag coefficient *cross sectional area of object moving through the air*velocity^2

Work=force*distance

The work the air is doing on the object converts kinetic energy (decelerating it) into enthalpy.

Temperature increase =
Work/(25.06*moles of titanium)= change in temperature

Moles of titanium= grams of titanium/47.867

These are the basics of what you would need to know to do the calculations. I simply took values from wikipedia.
Pick all the values you want (initial temperature of the titanium, distance the titanium is traveling through the air, etc). You should be able to look up values you need (such as density of the air).
The melting point of titanium would also vary depending on the pressure; you could factor this in as well.

This is simplified; the titanium would also be transferring and radiating away heat. Would probably be a good idea to incorporate this as well.

My understanding of physics is quite basic, so someone else would likely be able to help more with this.  8. There's no easy answer to this. How aerodynamic is the shape of the titanium? That is, what's its coefficient of drag? What is its surface roughness? How thick is the titanium? Is it actively cooled? How? What's behind the titanium? Etc, etc. Even though I don't know how to compute the answer for you, I've studied aerodynamics,, and it's much more complex than the original question.  Bookmarks
 Posting Permissions
 You may not post new threads You may not post replies You may not post attachments You may not edit your posts   BB code is On Smilies are On [IMG] code is On [VIDEO] code is On HTML code is Off Trackbacks are Off Pingbacks are Off Refbacks are On Terms of Use Agreement