Washing Your Hands
2645 cr points
Send Message: Send PM GB Post
24 / F / What? Your mom di...
Offline
Posted 11/16/09
I had a random thought the other day.

Is washing your hands fluid friction, or sliding friction?

Physical Science totally messed me up and now every time I see something I think "Static friction! Sliding! Oh oh oh rolling!" etc etc etc..

I apologize if this is a repeat thread or if I should have posted it in a different place. Go ahead and lock it if this is the case.
5229 cr points
Send Message: Send PM GB Post
25 / M / Mammago Garage, Y...
Offline
Posted 11/16/09
I guess it would be fluid friction since your hands are technically separated by a layer of liquid, even though it is an extremely thin layer.

Exactly how is this ED material?
Posted 11/16/09

oneweirdgirl wrote:

I had a random thought the other day.

Is washing your hands fluid friction, or sliding friction?

Physical Science totally messed me up and now every time I see something I think "Static friction! Sliding! Oh oh oh rolling!" etc etc etc..

I apologize if this is a repeat thread or if I should have posted it in a different place. Go ahead and lock it if this is the case.

Is there any fluid existing in between the surfaces of your hands? If so, then the situation is a fluid friction. Because when compared to the sliding friction force with your hands dried, the fluid friction force is weaker due to the fluid which exists in between the surfaces of your hand.

Mechanical physics is easy when you can correctly identify the situation. Static friction needs the existence of gravity, sliding friction needs a vector force for the sliding motion, and rolling friction is either a static or sliding friction with a centripetal force applied to an object.
55941 cr points
Send Message: Send PM GB Post
59 / F / Midwest, rural Am...
Offline
Posted 11/16/09
What about the surfactant properties of soap vs. just plain water? And then there's the issue of chapped hands.................

(What's the handwashing deal? H1N1 & or OCD?)
1580 cr points
Send Message: Send PM GB Post
26 / M / Texas
Offline
Posted 11/24/09

DomFortress wrote:


oneweirdgirl wrote:

I had a random thought the other day.

Is washing your hands fluid friction, or sliding friction?

Physical Science totally messed me up and now every time I see something I think "Static friction! Sliding! Oh oh oh rolling!" etc etc etc..

I apologize if this is a repeat thread or if I should have posted it in a different place. Go ahead and lock it if this is the case.

Is there any fluid existing in between the surfaces of your hands? If so, then the situation is a fluid friction. Because when compared to the sliding friction force with your hands dried, the fluid friction force is weaker due to the fluid which exists in between the surfaces of your hand.

Mechanical physics is easy when you can correctly identify the situation. Static friction needs the existence of gravity, sliding friction needs a vector force for the sliding motion, and rolling friction is either a static or sliding friction with a centripetal force applied to an object.


Why does static friction need the existence of gravity?
Posted 11/25/09

MCMXCI wrote:


DomFortress wrote:


oneweirdgirl wrote:

I had a random thought the other day.

Is washing your hands fluid friction, or sliding friction?

Physical Science totally messed me up and now every time I see something I think "Static friction! Sliding! Oh oh oh rolling!" etc etc etc..

I apologize if this is a repeat thread or if I should have posted it in a different place. Go ahead and lock it if this is the case.

Is there any fluid existing in between the surfaces of your hands? If so, then the situation is a fluid friction. Because when compared to the sliding friction force with your hands dried, the fluid friction force is weaker due to the fluid which exists in between the surfaces of your hand.

Mechanical physics is easy when you can correctly identify the situation. Static friction needs the existence of gravity, sliding friction needs a vector force for the sliding motion, and rolling friction is either a static or sliding friction with a centripetal force applied to an object.


Why does static friction need the existence of gravity?

Because that's how you conduct an experiment of a stationary object's static friction; on a slope:
1580 cr points
Send Message: Send PM GB Post
26 / M / Texas
Offline
Posted 11/25/09

DomFortress wrote:


MCMXCI wrote:


DomFortress wrote:


oneweirdgirl wrote:

I had a random thought the other day.

Is washing your hands fluid friction, or sliding friction?

Physical Science totally messed me up and now every time I see something I think "Static friction! Sliding! Oh oh oh rolling!" etc etc etc..

I apologize if this is a repeat thread or if I should have posted it in a different place. Go ahead and lock it if this is the case.

Is there any fluid existing in between the surfaces of your hands? If so, then the situation is a fluid friction. Because when compared to the sliding friction force with your hands dried, the fluid friction force is weaker due to the fluid which exists in between the surfaces of your hand.

Mechanical physics is easy when you can correctly identify the situation. Static friction needs the existence of gravity, sliding friction needs a vector force for the sliding motion, and rolling friction is either a static or sliding friction with a centripetal force applied to an object.


Why does static friction need the existence of gravity?

Because that's how you conduct an experiment of a stationary object's static friction; on a slope:


I'm a freshman physics major so I am probably completely off, but if you were in an environment with negible gravity, say in space, and there was a wood box with a powerful magnet inside of it and an iron box is resting on the surface of the box, wouldn't there be some static friction if the iron box was pushed parallel to the surface?
Posted 11/25/09

MCMXCI wrote:


DomFortress wrote:


MCMXCI wrote:


DomFortress wrote:


oneweirdgirl wrote:

I had a random thought the other day.

Is washing your hands fluid friction, or sliding friction?

Physical Science totally messed me up and now every time I see something I think "Static friction! Sliding! Oh oh oh rolling!" etc etc etc..

I apologize if this is a repeat thread or if I should have posted it in a different place. Go ahead and lock it if this is the case.

Is there any fluid existing in between the surfaces of your hands? If so, then the situation is a fluid friction. Because when compared to the sliding friction force with your hands dried, the fluid friction force is weaker due to the fluid which exists in between the surfaces of your hand.

Mechanical physics is easy when you can correctly identify the situation. Static friction needs the existence of gravity, sliding friction needs a vector force for the sliding motion, and rolling friction is either a static or sliding friction with a centripetal force applied to an object.


Why does static friction need the existence of gravity?

Because that's how you conduct an experiment of a stationary object's static friction; on a slope:


I'm a freshman physics major so I am probably completely off, but if you were in an environment with negible gravity, say in space, and there was a wood box with a powerful magnet inside of it and an iron box is resting on the surface of the box, wouldn't there be some static friction if the iron box was pushed parallel to the surface?

That wouldn't work, because now you've magnetic force instead of static force. And instead of a static friction ratio, you'll be required to calculate the moving friction ratio instead.
You must be logged in to post.