1. A skier has a mass of 80kg. He starts from rest and skis down a slope which drops 50m in height.
a) Calculate the amount of gravitational potential energy the
skier loses skiing down the slope.
b) What kinetic energy does he have at the bottom of the slope?
c) How fast is the traveling skier at the bottom?

this isn't the answer but they're the graphs

dang that balls went far

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.

+15-35=-20

going in opposite directions