Physics oh physics. I remember this one particular “practical application” physics midterm questions back in high school. It was something like this:

Bob is mopping the floor. His mop is angled 75 degrees from the floor and the coefficient of friction is 7 Newtons. How much force does Bob have to exert to get the mop moving?

Practical application? You know what’s practical? Bob pushing harder if the mop doesn’t move and easing up on it if it moves too much. That’s practical. What’s NOT practical is sitting down and figuring this thing out in Newtons or watts or whatever.

Yeah so I was like, “this is so stupid.” Of course I ended up getting a C+ or a B- in the class.

Fast forward almost ten years later, I use CoF (Coefficient of Friction) at work. Here are some pics I snapped to illustrate an example.

This is a bracelet (or cuff, if you will):

It needs to look a certain way on the website. It needs to face a certain way. It needs to angle a certain way. But we have a problem…

This is the stand/mount used to hold the bracelet up:

See that plastic surface? That’s smooth, real smooth.

See the inner side of the cuff?

That is also smooth. Now what happens when you place a front-heavy smooth-edged object on a smooth semi-cylindrical mount? It tips over.

That’s not exactly how cuff/bracelet shots are supposed to be angled, right? What to do? What to do?

Coefficient of Friction FTW. Rubber happens to have a really high CoF. Line the smooth surface with rubber (from a rubber band) like so:

And the cuff will stay put.

This works with opening stuck screw-on jar/bottle caps too. If you have a hard time opening a…say a jar of PB, get a wide/thick rubberband and wrap it around the cap…twist and enjoy. Don’t forget the jelly  ^_^