0
votes
1answer
46 views

Propulsion force [closed]

My physics instructor gave us a general problem A box is sitting motionless on a rough, horizontal patch of ground. You give it a good kick, so that it slides to the right with an initial speed of ...
21
votes
6answers
2k views

Why are rockets so big?

I'm curious why rockets are so big in their size. Since both the gravitational potential one need to overcome in order to put thing into orbit, and the chemical energy burned from the fuel, are ...
0
votes
2answers
142 views

How can thrust be generated in space which is a vacuum?

Since thrusters have no matter to push off of, how can a spacecraft generate thrust in the vacuum of space?