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- Thread starter MsHomework
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- #3

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How do I find that force?

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Andrew Mason

Science Advisor

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What is the force of the bullet? By your reasoning, the average force = initial force/2. Why would that be? You seem to be mixing up average velocity with average force.

(Instantaneous) Force = dp/dt = mdv/dt; Average force =?

AM

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You could apply the Work-Energy Theorem ...

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Can you tell me what it is? I don't really remember it!

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And work can be calculated with the following formula:

See if you can put those two together ...

See if you can put those two together ...

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d is for distance right?

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And yes, d is distance, in meters.

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F/\d = 1/2m(v2^2 - v1^2).

To solve for the net force, just divide by the distance.

F = (1/2m(V2^2 - v1^2))/(/\d)

But since the final velocity is zero:

F = (1/2m(-v1^2))/(/\d).

So make sure all the units are correct, substitute and done.

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Wait what is v1???

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The initial speed, before it hits the block. 320m/s.

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Oh ok.

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