Please help me to solve this problem... thx a lot b4 !!

1. A fully fueled rocket has a mass of 21,000 kg, of which 15,000 kg is fuel. The burned fuel is spewed out of the rear at the rate of 190 kg/s with a speed of 2800 m/s relative to the rocket. If the rocket is fired vertically upwards, calculate:

a. The trust of the rocket.

b. The net force on the rocket at blastoff, and just before burnout (when all the fuel has been used up).

c. The rocket’s velocity as a function of time.

d. Its final velocity at burnout. Ignore air resistance and assume the acceleration due to gravity is constant at g= 9.8 m/s2.