how does the friction force makes possible the motion of walking?

bump

Because with out friction your feet would just slip on the ground and you wouldn't go anywhere. Similar to walking around on an icerink in dress shoes. Even an ice rink has some friction though, you could move around if you do it slowly.

On a truly frictionless surface it would be impossible to move around with out some sort of propulsion or external object.

yup.
good answer.that makes sence.
but could u prove mathematically?

Sure do you know the difference between static friction and kinetic friction?

Supposing you were walking on asphalt, the kinetic friction force will be much greater than ice. Materials with little friction, such as frozen carbon dioxide (dry ice) and frozen water (ice) have a low frictional force, when compared to asphalt, concrete, or stone.

well i know that the static friction is some natural force that acts up some object when hes at repose.
its maximized when the object is about to move.
the kinect friction acts is the force that opposes to this movement when the object moves.
the kinect friction < static friction when this one is maxed.
i just wanted to see the math involved on this situation ^^

Well suppose a 50kg girl walks down the street with an initial velocity of 1m/s, for 20m until stopping at a candy store. What is the total frictional force exerted on the girl as she is walking? (assuming the coefficient of kinetic friction is .45)

See?

This post was edited by Jazz_Thing on Oct 12 2010 05:51pm

kinda.
but wont i assume any values 4 the static friction too?
arent the static friction applying some force when the girl steps on the floor?
looks like a system to me but i cant rly figure how it works ><

use the fun equation BRAAAAA



made this lol

This post was edited by shardoflard on Oct 12 2010 07:26pm

iso phorse Eqwalz Mew Emm Gee Etc.

http://answers.yahoo.com/question/index?qid=20100622172741AA4YAg2