Question

I wish to propel a rocket to 100,000 feet in altitude. Let's say the rocket weighs 20 lbs total. What is the amount of thrust I'd need to get it that high? Is there a formula for this?

Answer 1

I don't know this off the top of my head but I found this using the crafty internet search engines.
http://www.grc.nasa.gov/WWW/k-12/airplane/thrsteq.html

Answer 2

depends if you are taking into account air resistance??

Answer 3

Yes, but that is another question entirely. If you could answer both questions I'd be happy to have them.

How do you design the rocket to have as little drag as possible?

Answer 4

Here - get started in high power rocketry - there are many organizations and clubs http://www.nar.org/NARhpsc.html