Asinusoidal wave traveling in the negative x direction (to the left) has an amplitude of 20.5 cm, a wavelength of 28.5 cm, and a frequency of 15.0 hz. the transverse position of an element of the medium at t = 0, x = 0 is y = −3.00 cm, and the element has a positive velocity here. we wish to find an expression for the wave function describing this wave.

radiation

explanation:

heat is transmitted by radiation

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.