A ball on a rope is being swung in a horizontal circle at a constant speed. What best describes the work done by the rope?
F
The work done by the rope is dependent upon the speed at which it is rotated.
G
The work done by the rope is maximized and constant because centripetal force is constant
in this scenario.
H Since the ball does not move along the rope, there is no distance traveled and therefore no
work is done.
Since the ball is continuously changing direction, the rope is continuously doing work.

this is poiselle's equation from fluid mechanic in physics. mech eng

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.