A rocket has an initial mass of 32,000 kg, of which 20% is the payload. It burns fuel at a rate of 215 kg/s and exhausts its gas at a relative speed of 1.8 km/s.
(a) Find the thrust of the rocket.
(b) Find the time until burnout.
(c) Find the rocket's final speed assuming it moves straight upward near the surface of Earth where the gravitational field g is constant.