Suppose the gas in the explosion chamber of a rocket ship is kept at density ρ  and a pressure P1  and that it exudes from the chamber into empty space through an opening of area at one end of the rocket, find the thrust produced on the rocket ship:

The situation is somewhat contributed. But we assume that the instant gas exudes, it maintains its density in the chamberρ1 . Then, applying Bernoulli’s theorem between interior of chamber where v=0  and the point of degree (p=0)  and neglecting gravitational energy in space, we get: 0+12ρ1v2=P1+0 or v=2P1ρ1 Thrust = time rate of change of momentum. All particles exit with velocity v  and the mass of gas leaving per unit time is ρ1av .Rate of change of momentum=(ρ1av)v=ρ1av2=ρ1a2P1ρ1=2P1a