Find the equation of motion for a rocket fired vertically upward, assuming g is constant....

Find the equation of motion for a rocket fired vertically upward, assuming g is constant. Find the ratio of fuel to payload to achieve a final speed equal to the escape speed ve from the Earth if the speed of the exhaust gas is kve, where k is a given constant, and the fuel burning rate is . Compute the numerical value of the fuel-payload ratio for , and  equal to 1% of the mass of the fuel per second.