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

A .05 kg bullet hits a 4 kg block hanging 1.5 m from the ceiling, displacing it by a height of .50 m. What is the KE of the bullet before it hits the block, and what is the max PE of the block?

(So basically, a bullet hits a hanging block and makes it swing upwards by .50 m)

2. Relevant equations

PE = mgh

KE = 1/2 mv^2

3. The attempt at a solution

I wanted to use 1/2 mv^2 to find the KE of the bullet before hitting the box, but where would I get v from? I figured I could set something equal to the max PE of the block which I'm assuming is 4 (9.8) (.50), but how would I find v?

I figured the max PE of the block would just be mgh, so: 4 (9.8) (.50) But somehow that felt too easy, and I thought there should be more too it?

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# PE/KE-Bullet Hits a Hanging Block?

**Physics Forums | Science Articles, Homework Help, Discussion**