/sci/ - Science & Math

>>7571592
>From where does the spinning ball take the energy to move foreward?
pressure difference
do you not understand it at all?

I'm gonna go with both

better question is, could a space capsule reentering the atmosphere use the Magnus effect to slow their decent?

Also, if the ball is dropped from sufficient height will it spin so fast the centripetal force will tear it apart, or would terminal velocity limit it's spin?

>>7571636
well, i know that the air is flowing with the balls motion infront, and against it behind the ball, which generates a force, pushing the object foreward.

But the force pushing it foreward has to be 'generated' by some other force. Either the potentional energy or kinetic energy (which would both slow the fall). Or the 'rotational energy', which would slow the rotation.

the physical terms might not be correct. The question just popped up in my head this morning, and I wanted to know.

>>7571685
>But the force pushing it foreward has to be 'generated' by some other force
pressure gradient is a force

>>7571685
Why do airplanes fly? What force pushes them up?

>>7571687
This.

BUT

The pressure gradient is caused by the rotating object.
The object has to lose a form of energy to generate the pressure disparity around itself.

Interesting question..
I hope someone can enlighten us.

>>7571711
Same thing.

If the turbines were not running, there would be no pressure disparity. Same thing goes for the ball.
Question stands. Does the spin or the fall get slowed down?
Or in other words: Is the spin or the height the balls turbines?

>>7571716
Yes, it's coming from the ball's rotation. The Magnus effect works because the ball's spin moves the air with it; obviously moving the air requires a force, which in turn creates a force slowing down the spin of the ball.

a spinning makes lose a grip a bit causes turn flow

>>7571725
but it could also slow down the fall because the magnus effect is generating lift. Let's use a thought experiment to clarify exactly what OP wants to know: You have three balls, one in zero g allowed to spin in air, one dropped from a certain height without spinning it, and one dropped from the same height given the same spin as the first ball. Now the question is, will the second two balls hit the ground at the same time, and will the first and third ball stop spinning at the same time (we will assume the height is large enough to allow the air resistance to stop the spin before hitting the ground). It seems like the only one we can actually accurately compare are the second two balls, but if the second ball does hit the ground first, it DOES NOT mean the spin wasn't lowered. I'm sticking with what >>7571644
said I think it might be both.

>>7571725
>Yes, it's coming from the ball's rotation. The Magnus effect works because the ball's spin moves the air with it; obviously moving the air requires a force, which in turn creates a force slowing down the spin of the ball.
so if the ball rotates with respect to another axis, it go to another direction, such as up or left ?

>>7571800
>pic
I like kneeling philosophers in front of misaligned comics.

>>7571800
The axis of rotation would have to be perpendicular to the motion of the ball or else there would be no pressure gradient. It could in theory curve up, but that would take an immense spin, probably one that would make the ball's rotational velocity on the side parallel to its motion faster than its terminal velocity.

>>7571800
If you wanted it to curve left or right with respect to simply dropping it like in op's video, you would have to spin it at an angle to both axes so that it has top spin curving it forward, and then side spin to curve it sideways with respect to the forward motion

It's not horribly complex, I drew this in paint quickly to illustrate what happens.

bum

>>7572171
thanks m8, first time i've been on this board

>>7571723

Airplanes don't just fall out of the sky when their turbines shut off. It's airspeed that keeps the pressure difference and lift.

It's the same principle for the ball, only it's going straight down and powered by gravity