Objectives: To introduce the concept of dry friction To understand how dry friction works

Learning Outcomes:At the end of this session, student should be

able to: Briefly define what is friction Sketch a basic free-body diagram of a

normal friction

Definition:

“..a force of resistance acting on a body which prevents or retards slipping of the body relative to a second body or surface with which it is in contact”

Types of friction: Fluid friction Dry friction √

Law of Dry friction:“..occurs between the contacting surfaces of

bodies in the absence of lubricating fluid”

Characteristics of dry friction: Acts tangent to contacting surfaces In a direction opposed to the relative

motion In absence of lubricating fluid

SUMMARY Q & A