Problem 4: A model rocket (with mass m = 10 kg) initially at rest on the ground (Zo 0) is launched upward. The motion of the rocket is described by the following differential equations: er Th dt dt where t is time, z is altitude, w is velocity, and Th is the upward thrust due to the propulsion of the rocket and g is gravity. In this exercise, the upward thrust Th varies with time as follows: Th(t) = 670N for 0