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1. The problem statement, all variables and given/known data

A 11.7 g lead bullet is tested by firing it into a fixed block of wood with a mass of 1.15 kg. If the block and imbedded bullet together absorb all the heat energy generated and, after thermal equilibrium has been reached, the system has a temperature rise measured as 0.0230C°. Estimate the entering speed of the bullet.

2. Relevant equations

specific heat capacity of lead is .130 (I think)

specific heat of wood is 1700 J/kgK

KE=1/2mv^2

Q=mc*deltaT

3. The attempt at a solution

1.15kg --> 1150g

1700 J/kgK --> 1.7 J/gC

1/2*11.7*v^2=1150*1.7*.023 + .130*11.7*.023

I get that v=2.77, but it is the wrong answer. Please let me know what I am doing wrong. Thank you!

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# Homework Help: Bullet speed and thermal equilibrium

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