In addition to Ch7 momentum conservation, you'll need the work-energy theorem from Ch 6. The friction does work to slow the block down. Do this problem in two pieces: (1) immediately before and immediately after the collision, and (2) while the block slows down.
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i'm really confused on how to set up this problem and without that i can't get to the answer if someone could just help me figure it out!
Ok I think I understand it. Momentum is conserved, so m1v1 = (m1 + m2)(v2), where m1 is the bullet's mass, v1 is the bullet's velocity, (m1 + m2) is the mass of the bullet/block system, and v2 is the velocity of the system. We have all the masses, but need v2 in order to solve for v1. We can think that the surface does work on the block/bullet system to get it to stop moving. W = Fd, and in this case the d is given and F is just frictional force (which we can calculate). W also equals KE, since the work done in stopping the block completely erased its KE and energy never disappears.
So W = Fd = (1/2)m(v^2). In this case m is the mass of the bullet/block system, and v is v2, which is the missing thing we need.
thank you tons for helping me put it together now i see the picture i had the various components but i couldnt figure out how they fit thank you again!!!
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