People living wind farms sometimes object to them because of visual pollution and what other form of pollution?

noise pollution

Explanation:

Visual pollution may be defined as a pollution that obstructs a view. It impairs one ability to see and enjoy a pleasant view. It is considered as an aesthetic issue.

The rotating blades of the windmill causes visual disturbances by intercepting the light of the sun and it causes moving shadows and the light flashes from the reflection of the sun. It also causes noise or sound as the blades rotates. Thus the combination of visual and acoustics exposures leads to the negative assessment of the windmills.

Therefore, people living near wind farms objects the windmills as they causes visual pollution as well as noise pollution.

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.

find the sum of the two horizontal vectors and the sum of the two vertical vectors

isoceles right angled triangle