A test rocket is launched vertically from ground level (y = 0 m), at time t = 0.0 s. The rocket engine provides constant upward acceleration during the burn phase. At the instant of engine burnout, the rocket has risen to 49 m and acquired a velocity of 30 m/s How long did the burn phase last?

Question

Bullet

4 October, 03:16

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Answers (1)

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Sumo · Answer 1

I: x = 1/2at²

II: v = at

I+II: x = 1/2a (v²/a²) = 1/2 v²/a

a = 1/2 v²/x

v = 30

x = 49