Write a brief summary of table tennis or tennis

A point is won by a player when the opponent cannot hit the ball with a racket over the net and onto the other side of the table. Each game is won by being the first player to win 11 points, and be at least 2 points ahead of their opponent. The equipment needed to play table tennis would be a table, rackets, and balls. Some of the rules are no hand-on table (even leaning your hands on the table is not allowed!) Also, if the ball hits the net, you have to serve again.

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.