## Work energy power question

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

A pile driver has a hammer head of mass 4000 kg which is repeatedly raised 3.0 m above a pile and dropped onto it. The force required to drive the pile downwards into the ground is 500 000 N. When the hammerhead is dropped, all the energy foes into moving the pile. How far does the pile go with each blow?

2. Relevant equations

W= Fd
Et= Eg + Ek
Et= mgh + .5mv^2

3. The attempt at a solution

I found the total energy when the hammer is fully raised.

Et= mgh + .5mv^2
Et= (4000)(9.8)(3) + .5(4000((0)?2
Et= 117 600 J

then i did d= W divided by force to get distance

by slash isnt working for some reason so
117600 divided by 500 000=
=.2352 m
= 23.52 cm

The answer is supposed to be 25.5 cm though. I dont know what to do....

 PhysOrg.com science news on PhysOrg.com >> Front-row seats to climate change>> Attacking MRSA with metals from antibacterial clays>> New formula invented for microscope viewing, substitutes for federally controlled drug
 Recognitions: Gold Member Homework Help Science Advisor What about the hammer weight? It has potential energy at the start of the pile motion.
 I included it in the calculation. Please show me what you mean.

Recognitions:
Gold Member
Homework Help