## anonymous 4 years ago when we are standing still is there a frictional force asume the floor does have some co-efficient of static friction?

1. anonymous

no i think.....

2. anonymous

if there were no frictional force then we would be acceleration like in a ice skating....but what would be that forward force????anyone has an idea?

3. anonymous

there will be no friction as we are not moving and since friction opposes motion and there is no motion we wont have friction even though there is a coefficient of static friction

4. anonymous

oh sry i meant there is only static friction not limitic frition

5. anonymous

force is something that produces acceleration|dw:1326897225381:dw|

6. JamesJ

If the co-efficient of static friction were exactly zero, then just the very smallest muscle exertion you make to keep your balance would not find a compensating frictional force. In other words something as simple as taking a breath and trying to remain standing would result in your quickly losing balance and falling over. Hence the co-efficient of static friction on any surface one is standing is not zero.

7. anonymous

i know that the frictional force is limiting force,the maximum being the static friction but according to the value of applied force how does it change?

8. JamesJ

The force of friction for a stationery body isn't a constant. Consider the computer on the table in front of you. The force of friction acting on it right now is for all intents and purposes zero. Now, put your finger on the front of it and gently push. The computer doesn't move. Why? Because there is a force of static friction that acts in the opposite direction to the force of your finder. Push slightly harder and the computer still doesn't move, the two forces canceling each other out. Keep pushing harder until it does move, now the force of your hand on the compute is greater than friction. Hence the force of static friction depends on the force it is canceling out. If $$\mu_s$$ is the coefficient of static friction, the actually force of static friction ranges between zero up to its maximum, $$\mu_s N$$. I.e., $0 \leq F_{static \ friction} \leq \mu_s N$