A subway train is sitting in a station. It reaches its cruising speed after accelerating at 0.75 m/s2 for distance equivalent to the length of the station (184 m). It then travels at a constant speed
towards the next station 18 blocks away (1425 m).
1. Determine the train's cruising speed.
2. Determine the time it took for the train to accelerate from rest to its cruising speed.

as technology advances, new experiments often expose problems in accepted theories. c

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-lavira: )

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.