Draw the acceleration versus time graph for an object that is dropped from the top of a building and has no initial speed. label any known values. assume there is no air resistance. hint: the object is moving down so its acceleration will be negative.

When object is dropped from to of the building then during it fall the net force on it is only due to gravity which act downwards

so we will have

now we have

so during it's fall the net force force on the ball is constant and hence the acceleration is constant which is 9.8 m/s/s during its fall

Since there is no consideration of air drag so we have this value of acceleration to be constant through out the motion

and this graph will be a horizontal straight line for complete 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.