apply bernoulli's theorem to curved path of spinning ball(magnus effect)
Answers
Bernoulli’s principle :-
For an inviscid(non viscous) flow of a non-conducting fluid, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid’s potential energy.
So here’s why a spinning ball follows a curve flight
Consider top view of a spinning ball moving with some velocity towards left side. The ball is given a spin in clockwise direction. What you observe here is that – the top side of the ball the velocity of the fluid(air) is more than the velocity of air at the bottom side. Now, why ?
When the fluid comes contact with the upper side of the ball, the speed of air increases because the speed of ball adds to the speed of air(As the flow of fluid is in the same direction of spin).
When the fluid passes by the bottom side of ball, the speed of air decreases due to friction between both of them.
We see a velocity difference between both sides of the ball. Now according to Bernoulli’s principle, at the top side of the ball, due to high velocity a low pressure region gets created. This low pressure region pulls the ball with certain force – Magnus force. A spinning ball or cylinder curving away from it’s principal flight path is called Magnus effect. The Magnus effect is named after Gustav Magnus, the German physicist who investigated it.
In case of our example, the ball gets pulled upwards(because we are watching from top side). Actually, it is changing it’s path & following a curved one.