Bullet passing through block of wood. Find max height of the wood.

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Homework Help Overview

The problem involves a bullet passing through a suspended block of wood, with the goal of determining the maximum height the block will rise after the bullet passes through it. The scenario includes specific masses and an amount of work done during the interaction.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the use of momentum conservation to analyze the situation, while questioning the relevance of the work done on the bullet and block. There are attempts to derive a formula for height based on the given parameters.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the problem and attempting to clarify the role of the work done. Some guidance has been offered regarding the application of momentum, but no consensus has been reached on the final approach or calculations.

Contextual Notes

There is a lack of explicit equations provided in the original post, and participants are navigating the implications of the work done on the bullet and block, as well as the mass of the block being stated but not directly influencing the initial momentum calculations.

demenius
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Homework Statement


A bullet of mass 0.005kg is shot at a suspended block of wood with mass 1kg. The bullet initially has a speed of 200m/s, and passes through the block of wood. The bullet passes through the wood, and 50J of work is done deforming the shape of the bullet and block. If the block is suspended from a very long string, what is the maximum height to which it will rise?

http://imageshack.us/photo/my-images/266/bulletblock.png/"

Homework Equations


None given.


The Attempt at a Solution


I tried solving it using momentum before and after. But there is no mass given for the block and I do not know what to do with the 50J of work.
 
Last edited by a moderator:
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demenius said:

Homework Statement


A bullet of mass 0.005kg is shot at a suspended block of wood with mass 1kg. The bullet initially has a speed of 200m/s, and passes through the block of wood. The bullet passes through the wood, and 50J of work is done deforming the shape of the bullet and block. If the block is suspended from a very long string, what is the maximum height to which it will rise?

http://imageshack.us/photo/my-images/266/bulletblock.png/"

Homework Equations


None given.


The Attempt at a Solution


I tried solving it using momentum before and after. But there is no mass given for the block and I do not know what to do with the 50J of work.

In red
 
Last edited by a moderator:
I cannot believe I did not see that. :S. Thank you.
 
So would the height be equal to (v*mb/(mb+mw))^2 * 1/2g?

So. (200*0.005/(0.005+1))^2 *1/2(9.81) = 0.05m?
 

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