Arope of negligible mass is wrapped around a 225-kg solid cylinder of radius 0.400 m. the cylinder is suspended several meters off the ground with its axis oriented horizontally, and turns on that axis without friction. (a) if a 75.0-kg man takes hold of the free end of the rope and falls under the force of gravity, what is his acceleration? (b) what is the angular acceleration of the cylinder? (c) if the mass of the rope were not neglected, what would happen to the angular accelera- tion of the cylinder as the man falls?

i think the answer is a, hope this is right, that would be my best guess.

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.