Compressed air is used to fire a 50g ball vertically upward from a1.0m-tall tube. The air exerts an upward force of 2.0N on the ballas long as it is in the tube.
Q: How high does the ball go above the top of the tube?

Explanation:

Vertical Launch

If an object is launched vertical and upwards at an initial speed vo, it will start to go up as long as the speed is positive. The acceleration of gravity reduces the value of the speed until it goes to zero and the object reaches its maximum height.

The expression for the maximum height can be found with the equation

We need to find the value of vo given the conditions on how the ball was launched. It's known that the net force upwards makes the ball travel for y=1 m at an acceleration that can be computed by

Since

We can solve for v, that is the initial speed of launch

Thus, the maximum height is

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.