Solids Elasticity (Bulk Modulus)

asoz

1. The problem statement, all variables and given/known data
When the water freezes it expands by about 9.00%. What pressure increase would occur inside your automobile engine block if the water in it froze?(The bulk modulus of ice is 2.00 x 10^9 N/m^2).


2. Relevant equations
[tex]B=\frac{\Delta P}{\Delta V / V_i}[/tex]

3. The attempt at a solution
If I solve the problem "forward in time" I get this:
[tex]\Delta P=\frac{1.09V_i-Vi}{Vi}B=0.09B[/tex]

but if solving the problem "backwards in time"

[tex] \Delta P = \frac{V_i-1.09V_i}{1.09V_i}B = 0.0826B [/tex]

Shouldn't both answers have the same magnitude?

Mapes

No; 90% of 110% of x is not x, for example.

asoz

Of Course. Thanks