A wave has an amplitude of
0.0800 m and is moving 7.33 m/s.
One oscillator in the wave takes
0.115 s to go from the lowest point
in its motion to the highest point.
Find the frequency of the wave.
(Unit = Hz)

The frequency of wave is 4.34 Hz.

Explanation:

We know the relation:

                                 λ = = × ........................................1

where,

            λ= wavelength

            v= velocity of wave

            T= Period of wave

By the definition of period T, you are given that HALF of T is 0.115 s, so

T = 2 × (0.115 s)

   = 0.23 s

Then ,

                  λ = v × T

                     = (7.33 m/s) × (0.23 s)

                    ≅ 1.686 m

Now for frequency, return to equation 1,

    =

      =

      = 4.34

The frequency of the wave is calculated as 4.34 Hz.

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.