Question

QUESTION 2.10 If, instead, some fuel remains, at what height should the engines be fired again to brake the rocket's fall and allow a perfectly soft landing? (Assume the same acceleration as during the initial ascent.) EXERCISE 2.10 An experimental rocket designed to land upright falls freely from a height of 2.00 x 10 m, starting at rest. At a height of 80.0 m, the rocket's engines start and provide constant upward acceleration until the rocket lands. What acceleration is required if the speed on touchdown is to be vero? (Neglect air resistance.) ANSWER 14.7 m/s?

Answer 1

Solution, Exercise 2010 for highet (200 to 80) uro mls so 1201 a = 9.8 m/s2 2oom sa romah son varagh - 2x 9.88.130 1) 48-497 wls NOW V ua engines start cet som light Ur 48:497 wls at ground recall ati 8=80m vrouls vea u27 za5 (48.497) 27 2x ax 80 2 D 2352 - a 2x80 2. aa - 14.7 m/s du acceleration needed by engine 1407 m/s2