Summary: Name of School____________________________ Team Number____________________________
Team Member____________________________ Team Member ____________________________
Crave the Wave!
Your score will be based on your work (which you will show below) and not just the final answer.
1. (a) (10) Given the wavelength of the light from the laser pointer, the measured spacing between dots
along the wall, and the distance from the CD or DVD to the wall, calculate the spacing between the
grooves on the CD or DVD, in microns (to within about 10%).
(b) (4) Estimate the angular resolution of the human eye (when it sees by visible light), using the Rayleigh
criterion for the minimum angular separation that can be resolved. Assume that the resolution is limited
only by diffraction. You may give your answer in radians or degrees for full credit (even though
arcseconds is best).
2. (20) A long tube contains air at a pressure 0.98 atm and a temperature of 295 K. The tube is open at
one end, and closed at the other by a movable piston. A tuning fork near the open end vibrates with a fixed
frequency. Resonance is produced when the piston is at distances of 18.0, 55.5 and 93.0 cm from the open
end. These data show that a displacement antinode is slightly outside of the open end of the tube. How far
outside is it?
3. Using a flashlight, you shine a beam of white unpolarized light on the surface of a perfectly planar sheet
of clear ice that has formed atop a lake. The indices of refraction are 1.000 for air and 1.309 for this ice.
(a) (4) Let ! be the angle between your flashlight beam and the surface of the ice. What should ! be if
you want the reflected light to be completely polarized?