72. What is the physics behind a bowler rubbing the ball so many times before bowling it in the cricket match?
When bowler is rubbing one side of ball he is actually polishing or smoothening the surface of the ball. Other half of the ball remains as it is or more rough. When baller throws the ball at high velocity low pressure is created near smooth surface and high pressure area is created on rougher side. This pressure differential SWINGS ball in air and.... clean bowled! !!