what is a skidpad?

you drive the car around a circle of a certain size and they time you. this is a cliffnotes version of it and there is some math involved but i dont have time to reallly explain, im sure someone else can

It's a way to determine how well your car holds in the corners. They measure the breaking point for when you start to slide.

A skidpad, like junglistgsr said is a circle of a certain size (on flat ground). You can measure lateral acceleration at maximum cornering speed, steady state (constant radius) cornering ability, and understeer/oversteer. As for how it works, you drive the skidpad as fast as you can without losing it, then calculate how many g's you're pulling. Bampf can give you the equation if you're interested, I don't know it.

a skidpan is just a big concrete area in which tests are conducted on. usually lateral g's are recorded, or sometimes the area is watered down and you can just spin out, bag it up and the like.

1G is 9.81 m/s^2

32.2 ft/s^2