A manufacturing company has a plant located on a river. Although the waste water from the plant is treated before being emptied into the river, there is
concern byabout how the waste water might be affecting the health of the river
Construet an investigation and describe your procedure. IDENTIFY THE
PROBLEM, AND DECIDE WHAT THE DEPENDENT VARIABLE, INDEPENDENT
VARIABLE, CONSTANTS, AND ACONTROL WOULD BE l.

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.

could you add the photo?

explanation: