Approximation to the average velocity in that time interval, what should be the sequence of calculations?Update the (vector) position of each objectSpecify the initial (vector) position of each objectSpecify an appropriate value for the time step Update the (vector) momentum of each objectCalculate the (vector) forces acting on the objectsSpecify the mass of each objectSpecify the initial (vector) momentum of each objectDefine constants such as G

The steps are outlined in the explanation below.

Explanation:

The average velocity is derived midpoint from the initial to the final velocity. Here is the proof:

Find the total displacement:

let the displacement be given by the letter s

Then since the average velocity is defined as:  

where t = final time

           t₀ = initial time

           v = final speed

           v₀ = initial time

where x denotes the position, then

where v = and dx = change in distance with respect to time.

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.