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## Homework Statement

A 1.2- kg hammer hits a nail at a speed of 15 m/s and rebounds at 60 percent of that speed. The resisting force of the nail is 9000 N. Approximately how long is the hammer in contact with the head of the nail?

## Homework Equations

P=mv

Pf-Pi=Ft

## The Attempt at a Solution

This is what is was told to do:

Find P of hammer before, then find v after by mult.

by the % (60%= .60). Use that to find P after. add them,

then divide by the force to find time. deltaP=N*t

before: 1.2*15=18

18*.6=10.8

10.8*1.2=12.24

12.24+18=30.24

30.24/9000

answer=0.00336s

i don't understand why this answer is wrong

any help would be greatly appreciated.

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