Friction of water in a river

[radi6404 30]

I am interested how strong the friction is in a river which flows relatively fast, for example if you throw a key inside it or some other small metal peace, how long will it take til the friction starts removing atoms from the key and changing is physical structure. I am not talking about visual change, but when will the friction start removing layers from the stuff, since rivers are strong enough to even smoothen and remove stones after time.

 

I think the friction of it changes the surface of objects quickly, if the river flows fast.

[RTP 150]

I would say that the small metal piece would get carried away by the current rather than atoms being removed from it...

 

Any even if you fix it with something, the cohesive forces in a "small piece of metal" are quite large. The chance is much more likely that the current will break / interfere with a larger metal object before doing the same with a small one. Don't know if that explains it right. But a large object will break more likely than a small one...

[radi6404 30]

I don't know RTP, don't you think that the small metal peace will lay on the ground and water will flow over it, since it is much heaver than metal and even small stones that are not very heavy are not moved by the water.

[Ormion 439]

Are you talking about human bodies radi? It's better to throw them in the deep sea.

[Master Lu Bu 0]

Don't forget the concrete shoes

[Rotwang 326]

Trying to destroy satellite dishes again?

[reger 13]

Spot on, Rotwang, thats exactly what I was going to tell him !

[needle ninja 13]

The friction of water against anything pales in comparison to the friction of sand and stones within the water.

In any river sands and stones will be carried along with the water and the amount of friction they have are effected by both the speed of the water and the quantity turned up by disturbances.

[Padmapani 482]

for the friction of flowing water, you should use the colebrook equation: Colebrook equation