Example of kinetic force > static force

[PCSL]

Can someone give me an example of a case where kinetic force would be greater than static force? Thanks.

 

[inottoe]

Any object traveling faster than 0.866c will possesses kinetic energy greater than it's own rest energy (if this is what is meant btw).

 

[Dr_Morbius]

If I understand your question correctly then friction would be an example of a static force. It exists regardless of whether an object is moving or not. Drag would be an example of a kinetic force. It is only experienced by objects that are moving through a fluid or gas. As to whether one is greater than the other that depends on the situation.

 

[Studiot]

Can someone give me an example of a case where kinetic force would be greater than static force? Thanks

I expect you are referring to impact forces.

 

[my_wan]

In general a static force is a resistance between two forces.

static force = mass

Any object traveling faster than 0.866c will possesses kinetic energy greater than it's own rest energy (if this is what is meant btw).

static force = friction
Skateboard going down hill.

static force = tensile strength
A weight that breaks a rope used to suspend it.

static force = shear strength
Scissors cutting paper.

static force = gravity
An airplane in flight.

 

[PCSL]

I'm an idiot, I apologize. I meant friction.

So to rephrase my question: Can someone please provide an example where kinetic friction > static friction.

 

[rcgldr]

Can someone please provide an example where kinetic friction > static friction.

I'm not aware of any solids that have this behavior, although the static and kinetic friction can be close for some cases, like teflon on teflon, with a coefficient of about 0.4 for both.

There are control mechanisms called slide rails that use a fluid between the rail and a slider. The presence of the fluid results in resistance to movement that increases with speed, to elminate jerky movements for precise control. Some of these maintain the fluid by pumping the fluid through holes in the rail. This isn't really a case of static versus dynamic friction though.

 

[PCSL]

I'm not aware of any solids that have this behavior, although the static and kinetic friction can be close for some cases, like teflon on teflon, with a coefficient of about 0.4 for both.

There are control mechanisms called slide rails that use a fluid between the rail and a slider. The presence of the fluid results in resistance to movement that increases with speed, to elminate jerky movements for precise control. Some of these maintain the fluid by pumping the fluid through holes in the rail. This isn't really a case of static versus dynamic friction though.

Thank you.

 

[Julior71]

There is an interesting discussion on this forum around that topic...
https://www.physicsforums.com/showthread.php?t=140426