CBSE Class 11-science Answered
Any moving wheeled object will gradually slow down due to rolling resistance including that of the bearings, but a train with steel wheels running on steel rails will roll farther than a bus of the same mass with rubber tires running on tarmac. Factors that contribute to rolling resistance are the (amount of) deformation of the object, the deformation of the surface, and movement below the surface. Additional contributing factors include wheel diameter, forward speed load on wheel, surface adhesion, sliding, and relative micro-sliding between the surfaces of contact. It depends very much on the material of the wheel or tire and the sort of ground. For example, rubber will give a bigger rolling resistance than steel on some surfaces (polished steel) and a lower rolling resistance on other surfaces (pavement/tarmac). Also, sand on the ground will give more rolling resistance than concrete.