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MNWO

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A pile driver hammer of mass 170kg falls freely through a distance of 6m to strike a pile of mass 410kg and drives it 75mm into the ground. The hammer does not rebound when driving the pile. Determine the average resistance of the ground.

This is what i have done so far:

m1=170kg

m2=410kg

D1=6m

D2=75mm

PE= m x g x h

PE= 170 x 9.81 x 6

PE=10006.2J

Velocity=2 x g x s

(2) x (9.81) x (6-0)=117.72 square root=10.84 m/s

KE= ½ x mass x velocity

KE=1/2 x 170 x 10.84*

KE=9987.97J

Work= change in kinetic energy + change in potential energy + work due to friction

½ ( 170kg) ( 10.84*-0) + (150kg)(9.81m/s*) (6-0)

=18816.97N without work due to friction

Now I don't know how to work out: work due to friction and how to calculate the resistance of the ground. This is what I was able to do myself and now I am stuck.