Car tire skidding is when a car's tires lose traction with the road surface, causing the car to slide or slip instead of maintaining grip and control on the road.
Deceleration is the rate at which an object slows down. It is measured in meters per second squared (m/s^2) in the metric system or feet per second squared (ft/s^2) in the imperial system.
The symbol "uk" represents the coefficient of kinetic friction, which is a measure of the amount of friction between two surfaces in motion. In this context, uk = 0.8 means that the coefficient of kinetic friction between the car's tires and the road surface is 0.8.
A higher coefficient of kinetic friction (uk) means that there is more friction between the car's tires and the road surface, which can help prevent skidding. However, a coefficient of 0.8 is still relatively high, so there is still a risk of skidding if the car is traveling at high speeds or if the road surface is wet or icy.
To calculate deceleration using uk = 0.8, you can use the formula a = uk * g, where "a" is the deceleration, "uk" is the coefficient of kinetic friction, and "g" is the acceleration due to gravity (9.8 m/s^2 or 32.2 ft/s^2). In this case, the deceleration would be 0.8 * 9.8 = 7.84 m/s^2 or 0.8 * 32.2 = 25.76 ft/s^2.