- #1
Karol
- 1,380
- 22
Homework Statement
In a quartz longitudinal waves produce peaks on the 2 sides of the plate. the base frequency is:
##f_1=\frac{2.87E5}{s}##
Where s is the thickness. calculate Young's modulus of quartz.
[itex]\rho[/itex]=specific mass=2.66[gr/cm3]
Homework Equations
[itex]\lambda[/itex]=wavelength, u=velocity [itex]\lambda=\frac{u}{f}[/itex]
E=young's modulus, [itex]u=\sqrt{\frac{E}{\rho}}[/itex]
The Attempt at a Solution
I need to find the velocity u, but it depends on the length of the plate which i don't have. and even if i have the length, the frequency depends on the thickness. but since there is one Young modulus, since i was asked about, then there is one velocity.
If i write Young's modulus and the specific mass in their ingredients then the length cancels but then i have 3 other variables. and besides i am given [itex]\rho[/itex].