Question

why do you think rolling friction is less than sliding friction

Answer 1

Rolling friction is the resistance to motion experienced by a body when it rolls upon another. It is much less than sliding friction for same pair of bodies. When one body rolls upon another, there is theoretically no sliding or slip between them. And if both are perfectly rigid, there is no surface of contact....

Answer 2

bcs there is another forces which pushes the object and no matter how the surface is .. where as sliding friction has no other force on it