Physics

Problem

A data sheet lists both Young’s modulus

Y

and bulk modulus

B

for quartz. To find the speed of a longitudinal sound wave travelling along a long quartz rod, which modulus should be used in

v = \sqrt{E/\rho}

? a) Use

Y

only b) Use

B

only c) Use the arithmetic mean

\dfrac{Y+B}{2}

d) Use the product

\sqrt{YB}