An object moving in the positive direction experiences a net force in the direction opposite motion that delivers an impulse of -24 kg m/s in 4 seconds.
a. What was the magnitude and direction of the force pushing? (Treat force
as a vector.)
B. If the object had a mass of 2 Kg, what was the acceleration of the object?

it is a negative acceleration

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.

i think the answer is tomato juice? not entirely sure though