The index of refraction of a glass rod is 1.48 at T = 20.0°C and varies linearly with temperature, with a coefficient of 2.50 x 10-5/C°. The coefficient of linear expansion of the glass is 5.00 x 10-6/C°. At 20.0°C the length of the rod is 3.00 cm. A Michelson interferometer has this glass rod in one arm, and the rod is being heated so that its temperature increases at a rate of 5.00 C°/min. The light source has wavelength λ = 589 nm, and the rod initially is at T = 20.0°C. How many fringes cross the field of view each minute?

The index of refraction of a glass rod is 1.48 at T = 20.0°C and varies linearly with temperature, with a coefficient of 2.50 x 10-5/C°. The coefficient of linear expansion of the glass is 5.00 x 10-6/C°. At 20.0°C the length of the rod is 3.00 cm. A Michelson interferometer has this glass rod in one arm, and the rod is being heated so that its temperature increases at a rate of 5.00 C°/min. The light source has wavelength λ = 589 nm, and the rod initially is at T = 20.0°C. How many fringes cross the field of view each minute?