Which is not a characteristic of the cones in the eye? there are three kinds of cones. they are sensitive to color. they distinguish black, white, and gray. they need more light to function than rods.

They distinguish black, white, and gray.

Explanation:

In the human eye (specifically in the retina) there are two types of photoreceptors that convert light into electrical messages that are sent to the optic nerve, and then the image information is forwarded  to the brain. These photoreceptors are the cones and the rods.

It should be noted that the rods are more numerous and sensitive than the cones, but they are not sensitive to color. This type of cells is responsible for peripheral vision and in a low light condition.

On the other hand, there are three types of cones:

-Those sensitive to red light

-Those sensitive blue light

-Those sensitive green light  

Then, according to the explanation given and the options shown, the only one that is not true is:

They distinguish black, white, and gray.

volleyball players can not touch the net while the ball is in play

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.