I can't even understand what the hell this question is saying...
Something okorder /... It is easier to explain with a picture.
I would think the friction of rolling balls in a bearing is much less than the alternative. The points of contact distributed are individually much smaller, therefore less friction (wasted energy). Basically rolling vs rubbing or sliding.
Your question specifically asks about BALL bearings. (There are many other types of bearing). Most machines have moving parts. Moving parts cause friction. Friction causes heat and wear. Your question is saying. How can bearings minimise these problems ?...Here's a full explanation. A ball bearing has an inner and an outer raceway. (Like a track in which the balls will run). Bearings support the weight of the machine shaft that runs through the inner raceway. The shaft bearings are situated in lubrication (oil) baths within the machine casing. The lower half of the casing is now taking the full weight of the shaft and bearings. The AREA (due to their being spheres) of each of the balls in contact with the raceways is very, very small. Therefore the ability of the shaft to rotate with little friction, is far, far easier than a shaft rotating in full contact with another surface. There is still some friction and heat tends to build up..This is where the lubrication comes in.. The oil helps to reduce friction and carry away heat. It also seals against oxidation (rusting) of the metal and keeps it clean. (In weight I'm talking about Kilograms or tons or pounds as is normal in industry not Newtons as in scientific uses).
