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Why is my answer wrong? HELP PLS I HAVE MY EXAM TMRWboth questions pls

Why is my answer wrong? HELP PLS I HAVE MY EXAM TMRWboth questions pls-example-1
User Fadils
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1 Answer

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Step-by-step explanation:

1. You used conservation of momentum (Good!) BUT the block of wood and the bullet are now together and the mass = 1.9 + .1 kg = 2 kg

so

.1 kg * 600 m/s = (1.9 + .1) v

v = 30 m/s

2. Ball initial momentum = mv = .3 kg * 3 m/s = .9 kg m/s

on rebound momentum is nor .3 kg * ( - .2 m/s) = -.6 kg m/s

from .9 to - .6 is a change of 1.5 kg m/s

User Tomcheney
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