Aspeedboat travels from the dock to the first buoy, a distance of 20 meters, in 18 seconds. it began the trip at a speed of 0 m/s. by the time it reached the buoy, it was going 10 m/s. what was the average velocity of the boat? -3.33 m/s2 -1.11 m/s +1.11 m/s +3.33 m/s

e) none of the above answers are correct

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.