A pile is driven into the ground by means of a large mass of 450kg being raised to a height of 1.2m and released.
a) calculate the velocity of the mass just as it hits the piles (air resistance is negligible). The impact of the mass with the pile transfers 3500J of energy to the 1200kg pile. The impact drives the pile 0.14m into the ground.
I have 4.8 m/s as the answer to part a, which according to the answer scheme is correct.
b) Give a value for the force of friction between the pile and the earth (ignore potential energy of the pile in this example).
Answer for this part is 25 000N. No idea how to get there. Help, please?