time and graph u = 2000 m/s. If the fuel bums out in 50 s, calculate the acceleration at t = 0 s, 20 s, 40 s, and 50 s. uccm Tor it vaUS gm %3D 8.22. A rocket has a mass of m, and a mass ratio of R, burns at a rate of dmldt, and has an exhaust ve- locity of vo Find how long after ignition of the engines it will take the rocket to lift off from the ground. Calculate for the case in which mo is 5 X 10' kg, R is 3, the burning rate is 120 kg/s, and the exhaust velocity is 1000 m/s. 8.23. A lunar landing craft is hovering over the Moon's surface. One-third of its mass is fuel, while the mft nins out of fuel? Asume that