# Rolling friction

1. Nov 12, 2014

### avito009

You have to apply a force to counter the force of friction. In order to move fast the friction has to be reduced. So we have the invention of wheels. Rolling friction is much less than sliding friction. Experience shows that much less force is required to roll an object than to slide or drag it.

But wheels are not used in boats. why?

The friction on water is much less than that between solid surfaces. So because the friction is less the wheels cant be used.

So does that imply wheels are used when in contact with a surface where friction is more?.

2. Nov 12, 2014

### Meet

Actually wheel has got a feature that only 1 point of it should be in contact with the surface so it can perform rollng motion which is in fact stop and go motion.but in case of boat the whole wheels remain inside water so wheel there is of no use there is use of streamlined body to decrease the friction just like how plane have streamlined shape to reduce air friction. thus there would be no use of wheel in water as forces and frictional forces would be acting uniformly at the frontal part of wheel. Thats the reason turbines are not submerged fully inside water. this is what i think hope you got it

Last edited by a moderator: Nov 12, 2014