Wavelength. Each wavelength is a certain color. For instance, shorter wavelengths (like 470nm) will be blue or violet, while longer wavelengths (like 650nm) will be red. Hope this helps! :)
It will reflect because polished metal is like glass or water it’s shiny and smooth
Answer:
Abby is standing (4.5^2 + 2.3^2)^1/2 from the far speaker
D2 = 5.05 m from the far speaker
The difference in distances from the speakers is
5.05 - 4.5 = .55 m (Let y be wavelength, lambda)
n y = 4.5
(n + 1) y = 5.05 for the speakers to be in phase at smallest wavelength
y = .55 m subtracting equations
f = v / y = 340 / .55 = 618 / sec should be the smallest frequency