10 a home made solid propellant rocket has an initial mass of 91 kg 68

Question

10. A home-made solid propellant rocket has an initial mass of 9.1 kg; 6.8 kg of this is fuel. The rocket is directed vertically upward from rest, burns fuel at a constant rate of 0.23 kg/s, and ejects exhaust gas at a speed of 1980 m/sec relative to the rocket. Assume that the pressure at the rocket nozzle exit is atmospheric and that air resistance may be neglected. a) Fill in the following table. You must add other important independent variables to the 1ªcolumn; use you physical intuition and the given information above.
(b) the rocket velocity after 20 sec. (c) the rocket height H after 20 sec.