Mr. David drove from his home to his work place. For the first 1.2 hours, he travelled at a constant speed of 65 km/h. For the
next 2.3 hours, he travelled at a constant speed of 70 km/h.
What was the average speed for the whole journey?
km/h
Enter the answer

i think it's 35 meters

the inner core.

good luck: )

klicker

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.