What is the effect of friction

Friction and locomotion

Rubbing and sticking occurs in almost all situations in everyday life. Many people believe that friction is always a hindrance and undesirable. In many cases, however, there is an interest in rubbing or sticking occurring.

In the following tasks you should consider where rubbing or sticking is desired or undesirable on the objects mentioned. You should also state which measures will be used to achieve the desired goal.

If you can't think of anything to answer the questions asked, you can click on the "Show tip" button. An image then appears that may give you an idea. A possible answer is formulated in the "Show solution" field. Other solutions are also conceivable for some tasks.

task

a)

Where is sticking or rubbing desirable on the wheel of a car, and where not?

Good grip of the tire on the ground - suitable profile and suitable rubber compound.

Friction in the wheel bearing - use of ball bearings.

b)

Where is rubbing or sticking desirable when driving a bicycle, and where not?

 

Good adhesion of the foot to the pedal - e.g. rubber ribs on the pedal and good profile on the shoe.

Friction within the chain links - Well cleaned and oiled chain.

c)

Where is rubbing or sticking desirable in cross-country skiing, and where not?

 

Good adhesion of the ski in the imprint zone - e.g. scales or sticky wax in the imprint zone.

Friction outside the impression zone - application of glide wax.

d)

Where is rubbing or sticking desirable when playing football, and where not?

 

Good grip of the foot on the grass - use of cleats on the football boots.

Too much braking of the ball due to friction on the lawn - mowing the lawn for a short length or watering the lawn shortly before the game.

e)

When lifting loads with a pulley system, where is rubbing or sticking desired and where not desired?

 

Good grip of the hand on the pull rope - use of a "rough" rope.

Friction in the bearings and friction on the cheeks of the rollers - use of ball or roller bearings, use of sufficiently wide rollers.

f)

Where is rubbing or sticking desirable when walking, where is not desirable?

 

Good adhesion of the sole to the ground when pressing - use a profile sole made of adhesive material (e.g. rubber).

Low friction of the shoe when walking forwards - rolling possibility through a "curved" sole (especially with stiff mountaineering boots).