Practice MCQ Questions and answers on Physics-GK

Friction can be reduced by changing from sliding to rolling. Replace sliding friction with rolling element friction, such as with the use of rolling element bearings.

Main thing is that we find more friction on roads than on ice. As, we can call the friction as grip on roads. We can hear the word by tyre companies as the road grip tyres. Here the grip of the tyre is more than that of any normal tyre.

A ball rolling along the ground gradually slows down and finally comes to rest. It is the force of friction between the surface of the ball and the ground that brings the moving ball to rest.

The part which is tangent to the contacting surfaces is called the frictional force. Friction is a resisting force that acts on a body to prevent or retard its motion. Friction force always acts tangent to the surface at points of contact. Friction force acts opposite to the direction of motion.

A brake is a mechanical device that inhibits motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of friction.

Vehicle tyres are inflated properly to avoid skidding and to minimise friction.

Friction is caused by the irregularities on the two surfaces in contact.

The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. Reduce the friction as rolling friction is the least, rather than sliding or static friction.

The friction between two surfaces can be increased if the surfaces are pressed into each other with greater force. The harder the brakes are pushed, the harder the pads get pressed into the discs and the more friction is generated.

Rolling friction is caused by non-elastic effects.