Originally Posted By: paul
I ask you WHERE DOES THE MASS STOP?

It doesn't stop. This is why I said adding momentum is important. -1 + 1 = 0. Total is 0, but each part is non-zero.




Quote:

how would you add momentum then.

0+0=0 ?

would the total momentum of the spacecraft be zero even though the spacecraft is moving at 1000 kph?


You have to include the momentum of the exhaust. You have to include everything that interacts with the spacecraft in order to ensure momentum is conserved.

momentum_exhaust + momentum_craft = 0

That's not 0 + 0 = 0. I don't know why you're making ridiculous statements like the momentum of the spacecraft is zero. It's clearly moving so it's non-zero.

That's true throughout the acceleration and continues to be true while it's coasting.

Last edited by kallog; 09/09/11 02:24 AM.