Question

Earthquakes at fault lines in Earth's crust create seismic waves, which are longitudinal (P-waves) or transverse (S-waves). The P-waves have a speed of about 9 km/s. Estimate the average bulk modulus of Earth's crust given that the density of rock is about 2500 kg/m3

Answer 1

Answer:

$B=2.025\times 10^{11}\ Pa$

Explanation:

It is given that,

Speed of P- waves, v = 9 km/s = 9000 m/s

The density of rock is about $2500\ kg/m^3$

We need to find the average bulk modulus of Earth's crust. Let it is given by B. So,

$v=\sqrt{\dfrac{B}{d}} \\\\B=v^2d\\\\B=(9000)^2\times 2500\\\\B=2.025\times 10^{11}\ Pa$

So, the bulk modulus of the Earth's crust is $2.025\times 10^{11}\ Pa$.