Ball bearings are used in bicycles, cars, etc., because

2013

PhysicsXGeneral, Science and Technology

Ball bearings are used in bicycles, cars, etc., because

(a)

the actual area of contact between the wheel and axle is increased

(b)

the effective area of contact between the wheel and axle is increased

(c)

the effective area of contact between the wheel and axle is reduced

(d)

None of the above statements is correct

Explanation

The roundness of the bearings creates less contact between the bearing that is trying to move objects and the object being moved. A reduction in contact area means less friction.