Suppose a 52 cm diameter blade was attached to the motor shaft instead of the 76 cm diameter blade. If the fan blade experienced the same angular acceleration, what would happen to the magnitude of the tangential acceleration at the tip of the blade during the first few seconds

current and voltage can both be different in different parts of a circuit so it matters where you place the ammeter and voltmete

the part of the wave he is travelling on is the crest

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.