FRICTION (advantages and disadvantages)

Summary

Definition
Friction is a catchall word that refers to any force that resists relative tangential motion (or intended motion).
"Relative tangential motion" is a fancy way to say "slipping" or "sliding".
Its direction is opposite the relative velocity (or intended velocity).
Types
Dry friction
The resistive force between solid surfaces in contact that resists their relative tangential motion.
"Friction" is often synonymous with "dry friction".
Viscous friction-
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1. FRICTION By :- Akshat Trivedi 11th-A

2. 20/02/2014 2 Advantages and Disadvantages of Friction

3. Objectives… Explain why friction occurs. List the two types of friction, and give examples of each type. Explain how friction can be both harmful and helpful.

4. What is friction? Is a force that opposes motion between two surfaces that are in contact

5. When does friction occur? Friction occurs when two surfaces are in contact

6. Friction enables a car to move on road without skidding It is because of the friction between the tyres of car and the road which enables car to move forward without skidding. If there were no friction , car would stay where it was.

7. Why does friction occur? Because the hills and valleys of a surface are in contact with the hills and valleys of other surfaces, this produce friction.

8. What is Friction ? Friction (frictional force) is a force that acts in a opposite direction to movement. The force which always opposes the motion of one object over another, object in contact with it , is called friction.

9. Friction Enables Us to Write and Draw on Paper It is because of the friction between the tip of the pencil ( or pen) and paper. Carbon particles from the pencil lead rubs off from it, due to the friction, which appears as black marks on the paper.

10. Friction depends on… Roughness of surfaces and Force that objects are being pressed one against the other; or their weights

11. What increases friction? Rough surfaces And weight of objects

12. What does the amount of surfaces depend on? the amount of friction depends on how well the surfaces grip each other. Tyres on a road have very high friction (they don't slip), skates on ice have very low friction (they slip easily).

13. In a liquid or a gas For a solid object moving through a liquid or gas, the amount of friction depends on the shape and surface area of the object and the viscosity (thickness or thinness) of the liquid.

14. Car move due to the friction Friction enables a car to move on road without skidding It becomes sometimes difficult to drive and control car on wet road. This is because of water present on road reduces friction.

15. Friction Enables Us to Pick Up and Hold Things in Our Hands We can hold a glass tumbler in our hands because of friction between the tumbler and our hands. Similarly, we can pick up the books laying on the desk by our hands.

16. Friction Enables us to Light a Matchstick Friction also produces heat. We rub matchstick against the rough side of a matchbox, then friction between both of them produces heat and this heat burns chemicals present at the head of matchstick and it lights up.

17. TYPES OF FRICTION KINETIC AND STATIC

18. What is kinetic friction? Is the friction between two moving surfaces

19. Sliding and Rolling

20. Static friction It occurs when a force is applied to an object but this object doesn’t move.

21. 1.Friction enables us to walk without slipping It is because of the friction between the sole of the shoe and ground prevents us from slipping. While walking , we push the ground backwards and the force of friction acts in the opposite direction (i.e. in the forward direction) and prevents us from slipping. By making the balance.

22. Disadvantages of Friction Soil erosion caused by wind ( friction of a fluid). Holes in your shoes , jeans . ( friction of a solid ) high friction Lack of friction is dangerous too , you may fall if the floor is very slippy .

23. 1.Friction Wears Away the soles of Our Shoes When we walk on the road, tiny surfaces of the shoe keep on breaking off slowly due to which the soles of our shoes wear out slowly Due to which shoes get damaged and becomes unfit to wear.

24. 2.Tyres of Vehicles Wear out Gradually Due to Friction Like the shoe tiny particles of tyres also breakdown due to friction when they run on road. The same thing also happens with the bicycles Effect to Tyres Due to Friction

25. 3.Friction wears Out the Brake Pads of Vehicles Gradually Brake pad is made of rubber When the brakes of the vehicles are applied a lot of friction is produced Friction wears out the brake pads gradually Before - After

26. 4.Friction wears Out Steps Of Staircases in Building and Foot Over-Bridges The friction between the soles of the shoes and wear away hard stone steps slowly. Such type of staircase are usually seen at : Railway station Offices Old Buildings

27. 5.Friction Slows Down Motion Friction reduces the motion of moving parts of a machine . In fact all the moving things such as (cars , buses, airplanes, boats, ships ,etc.) are slowed down by friction.

28. Some ways to reduce friction

29. Some ways to increase friction

30. Conclusion Friction is a necessary evil We hate it sometimes but we also need it . It is very useful and but harmful too.

31. 20/02/2014 31 Advantages and Disadvantages of Friction

32. 20/02/2014 32 Advantages and Disadvantages of Friction