11.1 A two-stage, solid-propellant sounding rocket has the following properties:
First stage: m0¼ 249:5 kg; mf ¼ 170:1 kg; m_ e¼ 10:61 kg; sIsp¼ 235 s Second stage: m0¼ 113:4 kg; mf ¼ 58:97 kg; m_ e¼ 4:053 kg; sIsp¼ 235 s Delay time between burnout of first stage and ignition of second stage: 3 s.
As a preliminary estimate, neglect drag and the variation of earth's gravity with altitude to calculate the maximum height reached by the second stage after burnout.