What do u mean by pure rolling?

What is Pure Rolling : Rolling is a type of motion that combines rotation and translation of that object with respect to a surface , such that, if ideal conditions exist, the two are in contact with each other without sliding. Rolling is achieved by a rotational speed at the line or point of contact which is equal to the translational speed. When no sliding takes place the rolling motion is referred to as 'pure rolling'. Nevertheless, rolling resistance is much lower than sliding friction, and thus, rolling objects, typically require much less energ yto be moved than sliding ones. As a result, such objects will more easily move. One of the most practical applications of rolling objects is the use of Rolling-element bearings, such as ball bearings, in rotating devices. read less