The most common type of dam is an impoundment hydroelectric plant, which consists of a dam across a river, and a reservoir (lake) behind the dam. How does this type of dam work

A turbine spins the water to generate electricity.

Explanation:

This is impoundment facility is called a hydro electric power dam, it is basically a big hydropower system which uses the dam to store river water in a reservoir. The water released from the reservoir flows directly through a turbine, the turbine spins it, which afterwards activates a generator to generate electricity.

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.

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.