When s = 0.6 m, the spring is unstretched and the 10-kg block has a speed of 5 m> s down the smooth plane. determine the distance s when the block stops. determine the speed of the 100-kg crate when it rises to s = 15 m. the crate is initially at rest on the ground?

the answer is 3.1 his answer is wrong mines is right

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.

there are no contact forces mentioned on the list of choices that you've provided.