일반물리학 1 — Center of Mass and Linear Momentum: Problem 79

79 A rocket that is set for a vertical launch has a mass of 50.0 kg and contains 450 kg of fuel. The rocket can have a maximum exhaust velocity of 2.00 km/s. What should be the minimum rate of fuel consumption (a) to just lift it off the launching pad and (b) to give it an acceleration of 20.0 m/s^2? (c) If the consumption rate is set at 10.0 kg/s, what is the rocket speed at the moment when the fuel is fully consumed?