Two identical cans, one filled with lead shot and the other with feathers, are dropped from the same height by a student standing on a chair. which can, if either, experiences the greater force due to the gravitational attraction of the earth?

The lead shot-filled can experiences a greater force due to gravity because it contains more mass.

Explanation:

The gravitational attractive force that acts on two different bodies on Earth depends on the body's masses. The greater the mass, the stronger the force of gravity acts on the body. The smaller the mass, the weaker the force of gravity acts on the body.

The can with the lead shot in it has a greater mass than that of the can that is filled with feathers. Therefore, the can with the lead shot will experience a greater force due to gravitational attraction of the Earth than that of the can that is filled with feathers.

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.