How to Measure Constant and Average Thrust and Total Impulse?

Question

If a built a rocket which ways 10Kg with Propellant and the Propelllant ways 9Kg and It Burn for 2min at a rate of 75g/sec and most importantly tell me

HOW YOU WORKED THAT OUT.

And i dont want it that compilicated because then i will not understand the equation and the answer i just want it normal which you will be sure i can uderstand.

The Exhaust Velocity is 1307.553(The 3 goes on forever)m/sec

Answer 1

The thrust and impulse depend on a couple of things:

1. The mass rate (grams per sec) at which matter is expelled out the back end (call that R);
2. The SPEED (meters per sec) at which matter is expelled out the back end (call that V);

The thrust is then R·V.

The problem is, you have a value for R (75g/sec), but you didn't give a value for V.

The total impulse is (Thrust·Time). In your case, the Time is 2min; so total impulse is:

R·V·(2 min)
= (75g/sec)·V·(2 min)

But again, you need to know "V", the speed at which the exhaust comes out.