Solving for the Speed of an 8kg Bullet

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The problem involves an 8 kg bullet embedded in a stationary 9 kg block of wood, which moves at 40 cm/s post-impact. The collision is classified as inelastic since the bullet becomes lodged in the wood. The conservation of momentum principle is applied to determine the bullet's initial speed. Key equations involve momentum before and after the collision, emphasizing that kinetic energy is not conserved in inelastic collisions. The discussion seeks clarification on the collision type and its implications for momentum conservation.
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Homework Statement



An 8 kg bullet is fired into a stationary 9 kg block of wood which is free to move. The bullet is stopped in the wood which has a velocity of 40 cm/s after the impact. What was the speed of the bullet?

Homework Equations





The Attempt at a Solution

 
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use the conservation of momentum
 
Well we know from the question that the bullet gets lodged into the wood upon impact. What kind of collision would that be? Elastic or Inelastic? What kind of properties, specifically with conservation of momentum/kinetic energy does that collision contain?

Let me know if you need more help.
 
Thread 'Correct statement about size of wire to produce larger extension'

Thread 'Correct statement about size of wire to produce larger extension'

The answer is (B) but I don't really understand why. Based on formula of Young Modulus: $$x=\frac{FL}{AE}$$ The second wire made of the same material so it means they have same Young Modulus. Larger extension means larger value of ##x## so to get larger value of ##x## we can increase ##F## and ##L## and decrease ##A## I am not sure whether there is change in ##F## for first and second wire so I will just assume ##F## does not change. It leaves (B) and (C) as possible options so why is (C)...
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