Due to friction, the jar of a mixer becomes hot when it is run for few minutes.

(i) Rolling: The rolling wheels attached to luggage bags make it comfortable for passengers to carry them because rolling reduces friction and is smaller than sliding friction.
(ii) Sliding: By polishing surfaces or by applying a lubricant.

When a body rolls on other body, rolling friction comes into play.

(i) We sprinkle fine powder on carrom board to reduce friction.
(ii) Drops of oil are poured on the hinges of a door so that the door moves smoothly.

The treated tyres of cars and trucks provide better grip on the road.

The frictional force acts in opposite direction of motion. So, on sliding book, the direction of friction force is upwards.

The roller provides rolling friction instead of sliding friction. Since, the rolling friction is very less than the sliding one, hence, even a child can pull such piece of luggage easily.

When the object is at rest, we have to apply more force to interlock the irregularities. On the other hand, when the object starts moving the contact points on its surface do not get enough time to lock into the contact points on the ground. So it is easier to move the box when it is already in motion.

Due to very less friction on wet and smooth floor, our foot cannot make exact grip with the floor. Thus, it is very difficult for us to walk on this floor.

As we step on a banana peel, then there is no grip between our foot and the banana peel due to very less friction. So, we slip accidentally.

No, because friction depends on the nature of surface in contact.

The arrow with a pointed tip suffers small air resistance due to its pointed shape, so it moves faster.

Frictional force always act in the direction opposite to the direction of motion, so it will act towards west.

The rolling friction comes into play when one body rolls over the surface of another.

Friction is a necessary evil because it causes a lot of wear and tear.