(a) Friction opposes
the motion between the surfaces in contact with each other.
(b) Friction depends on the nature of surfaces.
(c) Friction produces heat.
(d) Sprinkling of powder on the carrom board reduces friction.
(e) Sliding friction is less than the static friction.
The direction of frictional force will be upwards acting opposite to the movement of the book.
If a bucket of soapy water is spilled on a marble floor, then it would make it more difficult for us to walk on a soapy floor because the layer of soap will make the floor smooth. The coating of soapy water will reduce friction between the floor and our feet, and our feet will not be able to get a proper grip on the floor, thus increasing chances of slipping and falling.
Sportsmen use shoes with spikes to increase the friction. Due to spikes in shoes, sportsmen do not slip while they run or play.
Seema will have to apply larger force because the heavy object will produce greater friction against the floor.
Sliding friction is always less than static friction. Friction comes into picture when irregularities on the surfaces of two objects get interlocked with each other. Two sliding objects find less time to get interlocked against each other’s surface irregularities. As a result, they experience less friction.
Friction as friend:
· Due to friction, we are able to walk on a surface.
· Due to friction between a pencil’s tip and a paper, we are able to write.
Friction as foe:
· Due to the friction, tyres wear out.
· Engines of automobiles consume more fuel due to the friction between different parts of the engines.
Any moving body in fluid experiences a force, which tries to oppose its motion that is known as drag or frictional force. This force depends on the shape of the body. Due to special shapes of objects, the force of friction can be minimised. Hence, it becomes easier for the body to move through fluids.