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Grinter1
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Could you tell me if i am right please and if I am wrong could you point out any mistakes?
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 doesn't 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. Homework 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
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 doesn't 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. Homework 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