Debye model with two distinct speeds. Suppose one preserved the distinction
between longitudinal and transverse waves in a crystal, assigning them speeds c/ and
ct. How would the results of the simplest Debye theory be modified?
For copper, the measured speeds are c/ = 4,760 m/s and ct = 2,325 m/s. The
average interatomic spacing is a — 2.28 X 10"10 meter. How does your predicted
value of 0D compare with the measured value?