50pts many points

dr. trout has noticed that the salmon in his fish hatchery seem to enjoy listening to the radio when he has it on in the lab. the fish in the tank closest to the radio seem to grow larger. dr. trout decides that the more music he plays, the faster the fish must grow. to test his idea, he sets up 5 large ponds with 100 salmon in each pond. he places a loudspeaker at the middle of each pond and plays various amounts of music in each pond. he is careful to play the same band, feed the fish the same diet, and keep the water conditions in all tanks exactly the same. after 10 weeks, he ends the trial and takes the average weight of the fish in each pond, and organizes his data in the table. the dependent variable in dr. trout's experiment is

a) hours of music.
b) weight of the fish.
c) diet of the fish.
d) size of the ponds.

B) weight of the fish. I know this because Dr. Trout is not measure how much music they listen to nor the size of the ponds. He is measuring how big the fish get by the end of the 10 week period.

Explanation:

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.