• Support PF! Buy your school textbooks, materials and every day products Here!

Calculate Bulk modulus

  • Thread starter Irishwolf
  • Start date
  • #1
9
0

Homework Statement



A rock at the surface has a density of 2600kg(m^(-3)
90000m down its density is 3100kg(m^(-3)
Change in pressure at the depth is due to hydrostatic pressure.
Whats the bulk modulus of the rock?



Homework Equations


Δp=p + ƿgh

Δp=-B(ΔV/V)


The Attempt at a Solution


Hydrostatic pressure:
p(90000)= 1 x 10^(5) Pa + (3100kg(m^(-3))(9.81m/s^(2))(90000m)
Δp= 2.74 x 10^(9) Pa

Δp= - B(ΔV/V)

So, (ΔV/V) => ΔV=m/ƿcompressed
And V=m/ƿintital

So the 2 m cancel and the expression for the bulk modulus is
-B=Δp(ƿcompressed/ƿinitial)
B= 3.3 x 10^(9)

I think I may have made a slight misktake please help?
 

Answers and Replies

  • #2
125
0
B has the right order of magnitude so I think you are fine.
 
  • #3
9
0
B has the right order of magnitude so I think you are fine.
Actually i made a mistake with the Vfinal expression.
My new answer is B= 5.3 x 10^(8)
 

Related Threads for: Calculate Bulk modulus

  • Last Post
Replies
1
Views
3K
  • Last Post
Replies
1
Views
4K
  • Last Post
Replies
2
Views
26K
  • Last Post
Replies
1
Views
4K
Replies
0
Views
2K
Replies
1
Views
2K
  • Last Post
Replies
1
Views
1K
Top