Ask MetaFilter questions tagged with friction

How do tanks turn efficiently?

Mike1024 — Tue, 04 Aug 2009 05:36:52 -0800

Tanks have long, high-friction tracks - good for going forwards, not so good for turning as the tracks would have to skid. What do tanks do to overcome this problem? It's reasonable to speculate that they have high-power engines, that they have a selection of low gears, and that they try to avoid making too many sharp turns, but are there any other design features that overcome this problem?

Gimme Friction

Robert Angelo — Sat, 30 May 2009 14:04:12 -0800

Need help keeping it up! My car sun visor, that is. My car is over seven years old, and the sun visor no longer stays up on hot days. Instead, it keeps falling down in front of my face. It turns on a metal rod attached to a plate that screws into the car ceiling. When it's hot weather, the thing loosens up and the visor refuses to stay in place. During most times of year, it's fine, but our Texas summer makes it droop.

I've tried tightening the screws, to no avail. I've tried putting pieces of velcro on top of the visor and on the headliner, thinking that would hold it up. The glue on the velcro comes off, leaving it stuck either on the visor or on the headliner.

Does anyone have any other suggestions? Maybe there's some sort of bizarro-backwards-antimatter version of WD-40 I could spray in it to give it more friction while still allowing it to be turned?

7th grade sex ed did not cover this!

Anonymous — Fri, 03 Apr 2009 08:52:02 -0800

Backstory: Since my very first copy of "Our Bodies, Ourselves", I have never, ever been able to understand exactly which parts of my nether regions were the hymen and which parts were 'the rest of me' so to speak. I now have a couple of months of sex with my first partner under my belt and the landscape is continuing to erode. What gives, and (when) should I worry? All kinds of TMI to be found inside! I am into about my third month of penetrative sex with my first partner, who is big in the penis department. We haven't measured, but he can't wear anything smaller than magnum condoms. He's been great about helping me adjust, doesn't rush me through foreplay etc. and has been generally awesome. The (always condom-ed) sex is really great once we get going, but about half the time it's painful right at the start (a stinging feeling near the entrance of my vagina). Adding more lube helps but doesn't eliminate this initial pain. Mostly I'm concerned about possible friction damage from this, or from toy/finger penetration...

Right now, the situation with my vaginal entrance is basically a rim with a number of small 'notches' running along the sides & bottom. I think this is fairly normal, since my gyn. who I saw about 2 months after starting to have sex didn't have anything to say about it. However, just inside is where things get a little confusing for me. Basically, I seem to be developing more texture just inside the entrance than I used to have, and I'm worried that it's actual damage from friction that is not supposed to be happening.

It's all within the first inch or so inside, and on the upper side of my vagina (toward the clitoris), on either side of what I think is my g-spot (the books were also not very good at explaining that part). What's prompting this question is that my boyfriend noticed a new little section of slightly separated tissue while fingering me. Previous changes had seemed more like texture variation, this feels like one or two small horizontal cracks in the vaginal wall, leaving a pea-sized area that can be wiggled around a little right next to the g-spot.

The area is not painful however (just weird-feeling), and I don't remember a specific incident where this might have occurred. My boyfriend noticed it while fingering me, but we're not sure how long it's been there, because it's not quite in the 'line of travel'. Since we're both n00bs we don't really have a metric for how vigorous our passtimes are relative to other people, but I'd guess we're on the more enthusiastic end of vanilla sex. So on the one hand, I'm well aware that my vagina is designed for penises to fit inside, and on the other hand I have absolutely no idea what's normal.

Things that would be very helpful:

1) Is this type of change normal, even after a while of having sex? Is what I'm experiencing actually just more hymen erosion, or something else?

2) What, if anything, should we be doing to prevent (or treat) this, if it's a problem?

Thank you!

throwaway email: hymenQmefi@gmail.com

Learn the Toilet Paper Dispenser Tricks of the Professionals for just $19.99!

WCityMike — Fri, 11 Jan 2008 12:37:23 -0800

You walk into a public toilet stall. There is a metal toilet paper roll holder. One of two annoying situations is happening. Either the bottom toilet roll is used up and the top toilet roll is still in its storage area.

Or the top roll is down and the bottom "roll" (even if it's just the cardboard tube) has not been removed, and the drag the bottom roll puts on the top roll causes the paper to break after one or two squares comes out.

It's a small annoyance, but a small annoyance I've had with these things for most of my life. Somewhere in the great Mefi User Database, there must be someone who just happened to somewhere along the line figure out the way to make these public metal toilet paper dispensers sing.

(Well, not literally.)

Any takers?

Bonus question: anyone develop a surefire way of preserving one's privacy when in a toilet stall where the door closes but won't lock?

Go ahead and fire all snark cannons for asking the question — but fess up, the answers'd be handy to you, too.

way better than sky-diving

clockzero — Tue, 06 Feb 2007 18:53:49 -0800

How could someone avoid burning up in the atmosphere while falling to Earth from orbit? Assuming they were not in a space shuttle. With the right sort of space-suit? Diving skills, aerodynamism? Is it possible?

Thigh-rubbing friction

Anonymous — Sun, 16 Jul 2006 11:36:35 -0800

For all the big-thighed women out there... In hot weather, do you have problems with wearing skirts sans pantyhose and walking any distance? If so, how do you deal with the inner-thigh chafing? I am not overweight by any means and am in fact quite fit, but I do have somewhat fleshy upper thighs that touch for about two inches below the groin area when I'm standing up. In the summer if I wear skirts without pantyhose, I can't walk more than six blocks without starting to get painfully chapped in that two inch area. It's really embarrassing. I do notice other women who have a similar physique to me "waddling" a little, ie walking with their legs a little wide. The way I avoid that is by cutting off the lower legs of black pantyhose and wearing this pseudo-thigh girdle under my skirt, and therefore eliminating the upper-inner thigh friction. I feel like such a weirdo for having to resort to such DIY solutions, but I am surprised that there is no undergarment product catering to this problem. No one else I know seems to have this problem, and even my heaviest girlfriends wear skirts all year round. (I can't just wear full pantyhose in the summer, because I wear sandals and pantyhose-toe is tacky and weird when you're just going to the beach.) I have been doing all sorts of exercises focusing on my inner thighs to try and slim them for the sole purpose of being able to wear skirts, but nothing is helping. Am I completely alone in this, or is there a method of dealing that I just haven't heard of? Please help me find a way to be a breezy skirt-wearer without the thigh-rubbing issue!

the smooth mouse buttons syndrome

a007r — Sun, 30 Apr 2006 09:29:53 -0800

I noticed that as times goes by, computer mice (and other plastic items) get used by skin friction. I notice my mice have "smooth" areas on their buttons that obviously seem to be there because of use. Is there a way to prevent that? Now, that's not a big deal, but it's annoying, because, the mouse being smooth, my logical deduction is that finger grease or filth of some kind can be felt much much more easily when the surface is smooth. Maybe I'm crazy, but I noticed some kind of "dirt bumps" that can be scratched off, but they come back pretty quick and I have to wash my hands, wipe the mouse buttons, scratch the little "mouse poo" as I call it, and then I'm ok for maybe a little while.

This problem has annoyed me a lot more since I bought a logitech MX510, which has a glossy surface. This thing has no texture, so I feel the dirt a lot more!

So, the question might be as follows:
a) is there a way to prevent this?
b) are there furry mice (computer mice huh, not living ones), kind of like the furbook? :)
c) am I just crazy or this does annoy some people out there? I always feel like "my hands are dirty" because of this.
d) are there computer mice out there that are more resistant (like, they will never loose their texture) to this effect? If so, could anyone advise me of their experiences?
e) should I wear gloves or consult a psychiatrist? :)

What I need a mouse to do is simply to have silent, easily clickable buttons, a silent mousewheel (requires no effort), and one additional button, because I am a Linux user who uses XGL and Compiz. What that means is that I can't live without my dear "scale" plugin (that does the same thing as the Exposé feature of Mac OS X) being mapped to a button of the mouse.

My sofa cushions need more friction

junkbox — Mon, 12 Sep 2005 08:10:01 -0800

Help me stop the cushions on my IKEA Ektorp sofa from sliding forward. My sofa has removable seat cushions and back cushions, and a fold-out sofa bed. The area underneath the seat cushions is a very smooth vinyl; consequently, the cushions "creep" forward whenever you sit down, stand up, or squirm around, leaving you with several inches of unsupported cushion just hanging there stupidly. Pushing them back into place every night, sometimes multiple times a night, is getting quite frustrating.

I want to put something on this vinyl surface or on the forward edge to cause more friction and prevent the cushions from sliding. It should be affordable, it should last at least 6mos-1year, and it should not damage the underside of my seat cushions. I'm wondering if some kind of double-sided rug tape might work, but that stuff never struck me as being very effective. Better ideas?

Guess the number and win a sculpture!

~rschram — Thu, 10 Mar 2005 09:08:54 -0800

How does this work? I saw a similar piece recently in person, and the explanatory note said that the materials were "Pins held together by friction and gravity."