Could you tell me if i am right please and if im wrong could you point out any mistakes?(adsbygoogle = window.adsbygoogle || []).push({});

A pile-driver hammer of mass 150kg falls freely a distance of 5m to strike a pile of mass 400kg and drives it 75mm in the ground. The hammer doesnt rebound when driving the pile. Calculate the average resistance of the ground. You are required to solve this problem by:

(a)By making use of the principle of conservation of momentum and D'lamberts principle

2. Relevant equations

v=u+at

v2(squared)=u2(squared)+2as

S=ut+0.5at2(squared)

f=m*a

3. The attempt at a solution

a)

Hammer mass=150kg

Falls freely= gravity = 9.81

Distance= 5m

pile mass =400kg

depth= 75mm= 0.075m

no rebound

Average resistance= ???

M1*U1+M2*U1=M3*V1

(150*9.81)+(400*0)=1471.5 m/s

a=v(squared)-U(squared)/2*5

a= 0.981

f=m*a

f=147.15

FR=f-m*a-m*g

FR= -5395.5

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# D'lamberts Question.

**Physics Forums | Science Articles, Homework Help, Discussion**