Science behind rotating ball

Magnus effect

Players of TENNIS and CRICKET often feels that, when a ball is thrown then it does not follow a straight line but it follows a curved path, WHY???

i'll explain it,why a cricket ball follows a curved path.

when a ball is thrown then an effect works behind it called MAGNUS EFFECT

i'll explain it by a figure so that i can make it easier

The movement of ball on curved path is called SWING.

When a, thrown ball moves ahead,then empty space left behind the ball is filled by the air rapidly.
Let the air velocity is "v" (air going to fill the empty)
If the ball is spining with velocity "u" then the air around the ball is also moving with velocity "u"
Then as shown in the figure, the velocity of lower side of the ball is "u+v" and of upper side is "u-v"
It results that, pressure on upper side of the ball is greater than the lower side(BERNOULLI'S THEOREM)
Due to this pressure difference the ball moves in a curved path.
This is called MAGNUS EFFECT.
Bowllers use this trick behind swing the ball, spin the ball.
famous bowler Zaheer Khan,Murlitharan,Shane warn are known for there bowlling all over the world.