- #1
Lord Anoobis
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Homework Statement
The last stage of a rocket, which is traveling at a speed of 7600m/s, consists of two parts that are clamped together: a rocket case with a mass of 290.0 kg and a payload capsule with a mass of 150.0kg. When the clamp is released, a compressed spring causes the two parts to separate with a relative speed of 910.0m/s. What are the speeds of
(a) the rocket case and
(b) the payload after they have separated? Assume that all velocities are along the same line.
Homework Equations
m1V1i + m2V2i = m1V1f + m2V2f
Vac = Vpc + Vap
Subscripts being ac=case velocity according to A, pc=relative velocity between case and payload, ap=velocity of payload according to A
The Attempt at a Solution
Howdy folks, I hope I haven't botched the equation writing part, being a newcomer here.
I took the perspective of an observer, A, and used the Galilean transformation for velocity which resulted in
Vac = 910 + Vap
Then with the conservation of momentum:
150Vap + 290Vac = 440(7600), 440kg being the total mass.
Solving for the case's velocity gave an answer of 7910m/s with the correct answer being 8200m/s. I noticed that dividing the relative speed of 910m/s in the same ratio as the masses gives the correct answer. Two attempts at the problem without success so far.