Page 1612 - College Physics For AP Courses
P. 1612
1600 Answer Key
Square each equation to get
Add these two equations and simplify:
Multiply the entire equation by to recover the kinetic energy:
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The force needed to give a small mass an acceleration is . To accelerate this mass in the small time interval at a speed requires , so . By Newton’s third law, this force is equal
in magnitude to the thrust force acting on the rocket, so , where all quantities are positive. Applying
Newton’s second law to the rocket gives and unburnt fuel.
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(a) 0.421 m/s away from the ejected fluid. (b) .
Test Prep for AP® Courses
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(b)
3
(b)
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(a)
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(c) (based on calculation of )
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(c)
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(d)
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(b)
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(d)
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(b)
, where is the mass of the rocket
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