## Tuesday, November 13, 2012

### University of Sydney - Comparative Analysis of the COR of a Super Ball and a Tennis Ball

This is a cool comparison of the physics of the bounce of a Super Ball and a Tennis Ball.
Enjoy,

The Founders

### Coefficient of Restitution

$C_R = \frac{v}{u}$

Dear Sphaeralogists,

This formula is the key to what makes the SuperBall so special and such darned-tooting good fun.  Essentially it measures the velocity of return of an object dropped, thus indicating the amount of energy maintained after it has struck a surface.  The higher the number, the bouncier the object.  Some studies have measure the Coefficient of Restitution of the Super Ball® at .92.  This is extremely high in physical terms and indicates that there is tremendous bounce in these here balls.  This measurement is only considered with the balls dropped without propulsion.  As we know, a little kick can really make these spheres soar.  Consider this wiki entry for more on this subject:

You can also use this formula to measure the COR, this time a measure of return height:

$C_R = \sqrt{\frac{h}{H}}$

Here is one study of the measure of the COR of the Super Ball conducted at Colorado State:

They used this formula as their basis of measurement.

In any case, the science of the bouncy ball is very cool and worth a look see, so you should all take a gander to brush up on the true nature of your favorite ball.

Sincerely,

The Founders

### HowStuffWorks - SuperBalls

"A dark purple sphere about the size of a plum, Super Ball has already bounced into millions of U.S. homes, shows no signs of slowing down. McGeorge Bundy bounces Super Balls in his Washington basement, brokers on the Pacific Coast Stock Exchange throw them about the floor during slack hours, Manhattan executives dribble them on their desks, and kids around the country are bouncing them down sidewalks and school corridors."

-   Time magazine, 1965.

Check out the article on HowStuffWorkd.com about the science and history of the SuperBall.

HowStuffWorks

There is some really geeky stuff here for you to dork over.  So enjoy and learn.  The one thing missing here is an understanding of the Coefficient of Restitution, for which the Original SuperBall is legendary.

Best,

The Founders

## Wednesday, October 3, 2012

### I.S.S. Jewelry: The Final Final Installment

These are truly the last of the available Sphaeragemmae collection pieces.  Get 'em!

- The Founders