Swimming in circles

>>9056900
They always swim against the flow. There's an artificial current in the tank created by the pump.

>>9056952
Ok. Didnt know that. But theoretically. If there were no artifical stream, and they were floating on their own, which direction would water spin?

>>9056954
Clockwise.

File: 3d-optical-illusion-sand-art-jamie-harkins-1.jpg (171KB, 880x660px) Image search: [Google]

171KB, 880x660px

>>9056954
Then you need to know how much force they are applying with their fins verses how much drag they are causing on the water as the fish move through it. Since their fins push enough, to overcome the drag on the fishes' bodies, the water will flow in the direct from head to tail fin. The amount of flow is negligible, but exists. Immediately after passing the fish the flow reverses as well as negates. This is because of Newton's third law.

The main problem here is that without an initial flow, or outside intervention (scaring them in one direction for a long time), the fish won't all start swimming in the same direction.

If a human stands in a pool and starts running around it a huge flow can be created to make a whirl pool (friends and I did this in our pool all the time). This is because the human's feet are in contact with the ground. If the same thing was tried with people swimming free it wouldn't work.

>>9057116
Thank you good man.

>>9056900
clockwise.

they push themselves forward with tail, so a minor current is created backwards

>>9057116
>>9057279
Water and air is non newtonian. The water moves in the same direction as the force applied. Drag your finger through water in a circle, the water moves with you. Accelerate your car with a balloon in it and the balloon moves forwards, not backwards like you being pushed in your seat.

>>9057116
how could they make the drawing without putting footprints in the sand?

also, im pretty sure when i stir my coffee in the morning the water swirls in the same direction that i stir

>>9057292
but this is different.

your finger is not being propelled forward by propelling water backwards, as fish do.

put a propeller in water and the water surely moves backwards.

A balloon moves forward in an accelerating car due to buoyancy. As you accelerate forward ALL the mass is dragged backwards (including the balloon), this is simple inertia. Air is heavier than a helium balloon causing the air to displace the balloon, making it move forward. the balloon is still feeling a force to drag it backwards simply the force of buoyancy is stronger.
>https://physics.stackexchange.com/questions/86774/why-does-a-helium-filled-ballon-move-forward-in-a-car-when-the-car-is-accelerati

>>9057299
you have to be trolling, nobody can be this stupid.

>>9057299
>putting things in coffee
Baka

>>9056900
Conservation of angular momentum would make the water go clockwise.

it must move clockwise just slightly though.

>>9057485
neither the water nor the fish move. it causes the entire universe to rotate around the fish in the water.

>>9057433

i don't remember much from mechanics, how does friction affect the water's movement if we're not talking about frictionless water and fish?

>>9057433
But the fish are converting chemical energy to mechanic energy like a motor, so momentum conservation does not apply. Cars start at 0 speed but start to move once driven...

>>9057902
I was trolling btw, that was a joke, yeah, really.