Final answer:
Sliding friction is a type of kinetic friction that occurs when two objects slide against each other, with examples including pushing a book across a table or a box sliding down a ramp. Sliding friction is caused by the contact points of surfaces interlocking, with static friction being greater than kinetic friction as demonstrated by chalk screeching on a board.
Step-by-step explanation:
Examples of Sliding Friction
Sliding friction occurs when two objects slide against each other. This type of friction is kinetic friction and it acts in the opposite direction of the sliding motion.
For example, when you push a book across a table, the resistance you feel is caused by sliding friction. This friction is the result of the microscopic contact points on the surfaces of the book and the table interlocking with each other, opposing the motion.
A common illustration of sliding friction in action is seen on an inclined plane. For instance, a box sliding down a ramp experiences sliding friction that opposes its downward motion.
As the box slides, the surface roughness of both the object and the ramp, as well as the adhesive forces between their surface molecules, contribute to the magnitude of the sliding friction.
Another example is the sudden screeching of chalk on a chalkboard. This noise is due to the chalk sticking and then slipping as a result of the difference between static and kinetic friction.
Static friction is stronger than kinetic friction, causing the chalk to momentarily stick before slipping again, which produces the characteristic screeching sound.