Lag1989 task №3.23

The initial mass of the rocket is m₀ = 200 g, the mass of the charge is m = 180 g, the initial velocity of the rocket is zero, the relative exit velocity of the combustion products of the nozzle is u = 30 m / s. Neglecting air resistance and the acceleration of free fall, find the speed of the rocket at the time of full charge burnout.