The force of gravity pulls down on your school with a total force of 400,000 newtons. The force of gravity pulling down on your school would be exactly twice as much if your school:

Explanation:

It is given that, the force of gravity pulls down on your school with a total force of 400,000 N.

The force of gravity is given by the formula as follows :

F = mg

m is mass and g is the acceleration due to gravity

Mass of an object remains same always. But if the mass of your school becomes twice of the initial mass, the force of gravity pulling down on your school would be exactly twice.

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.

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.