CBSE, NCERT, JEE Main, NEET-UG, NDA, Exam Papers, Question Bank, NCERT Solutions, Exemplars, Revision Notes, Free Videos, MCQ Tests & more.Install Now
Friction class 8 Notes Science in PDF are available for free download in myCBSEguide mobile app. The best app for CBSE students now provides Friction class 8 Notes Science latest chapter wise notes for quick preparation of CBSE exams and school-based annual examinations. Class 8 Science notes on chapter 12 Friction Science are also available for download in CBSE Guide website.
CBSE Guide Friction class 8 Notes Science
CBSE guide notes are the comprehensive notes which covers the latest syllabus of CBSE and NCERT. It includes all the topics given in NCERT class 8 Science textbook. Users can download CBSE guide quick revision notes from myCBSEguide mobile app and my CBSE guide website.
Class 8 Science notes Chapter 12 Friction
Download CBSE class 8th revision notes for chapter 12 Friction in PDF format for free. Download revision notes for Friction class 8 Notes and score high in exams. These are the Friction class 8 Notes prepared by team of expert teachers. The revision notes help you revise the whole chapter 12 in minutes. Revision notes in exam days is one of the best tips recommended by teachers during exam days.
CBSE Class 8 Revision Notes Science Friction
Friction is a force that opposes the relative motion between two surfaces of objects in contact. The force of friction always acts in a direction opposite to that of the applied force.
Causes of Friction: Friction exists between two surfaces due to irregularities on the surfaces of the objects in contact, interlocking of micro-level irregularities of the two surfaces and ploughing of harder surfaces into smoother surfaces.
Factors That Affect Friction
• Roughness of the surface
• The extent to which the two surfaces press together
• Nature of the surface
Types of Friction:
(i) Static Friction: When a body is at rest, the force of friction is called the static friction and is always equal and opposite to the applied force. The force of friction which acts when the body is just at the verge of sliding on the surface is called limiting friction.
(ii) Sliding friction: The friction force which opposes the actual relative sliding motion between two contact surfaces. Sliding friction is smaller than static friction.
(iii) Rolling Friction: The frictional force that exists between two surfaces when a body rolls over the other. Rolling friction is smaller than sliding friction.
Effects of Friction
• Friction produces heat.
• Friction causes wear and tear.
• Friction opposes motion.
Advantages of Friction
• Friction between pen and paper enables us to write on the paper.
• Friction between our feet and the ground allows our movements like standing, walking and running.
• Friction between the surface of the road and tyres of our vehicles allow the vehicles to move without slipping.
Disadvantages of Friction
• Friction causes moving objects to stop or slow down.
• Friction produces heat causing wastage of energy in machines.
• Friction causes wear and tear of moving parts of machinery, soles of shoes, etc.
Friction is a necessary Evil: As friction is advantageous to us it is considered as a friend but due to its disadvantages it is a foe. Depending on the circumstance, friction can be a help or a hindrance. Thus it is a necessary evil.
Increasing Friction: By pressing the surfaces together more strongly. For e.g. when brakes are applied on a bicycle or car, the brake pads press against a moving part of the wheel and the force of friction increases.
Friction can be increased by increasing the roughness of the surfaces in contact. For example, treading of shoes and tyres is done to increase friction.
Reducing Friction: Friction between the sliding surfaces of two objects can be reduced by making the surfaces in contact smooth by polishing them.
Sliding friction between the moving parts of vehicles and machinery can be reduced by using oil, grease, graphite or any other lubricant.
Rolling friction is less than sliding friction. Hence, sliding friction is replaced by rolling friction by using rollers, like ball bearings between the hub and the axles in the moving parts of machines and vehicles.
Friction is reduced by providing wheels, e.g. suitcase, school bags of kids, etc.
Aeroplanes, boats, fishes, and birds which move through fluids have bodies of special shape, called streamlined shape, so as to reduce the friction due to fluid and avoid energy loss.
CBSE Class 8 Revision Notes and Key Points
Friction class 8 Notes Science. CBSE quick revision note for class 8 Science, Chemistry, Math’s, Biology and other subject are very helpful to revise the whole syllabus during exam days. The revision notes covers all important formulas and concepts given in the chapter. Even if you wish to have an overview of a chapter, quick revision notes are here to do if for you. These notes will certainly save your time during stressful exam days.
To download Friction class 8 Notes Science, sample paper for class 8 Science, Social Science, Science, Science; do check myCBSEguide app or website. myCBSEguide provides sample papers with solution, test papers for chapter-wise practice, NCERT solutions, NCERT Exemplar solutions, quick revision notes for ready reference, CBSE guess papers and CBSE important question papers. Sample Paper all are made available through the best app for CBSE students and myCBSEguide website.
- Crop Production and Management class 8 Notes Science
- Microorganisms class 8 Notes Science
- Synthetic Fibres and Plastics class 8 Notes Science
- Materials: Metals and Non-Metals class 8 Notes Science
- Coal and Petroleum class 8 Notes Science
- Combustion and Flame class 8 Notes Science
- Conservation of Plants and Animals class 8 Notes Science
- Cell-Structure and Functions class 8 Notes Science
- Reproduction in Animals class 8 Notes Science
- Reaching the age of Adolescence class 8 Notes Science
- Force and Pressure class 8 Notes Science
- Sound class 8 Notes Science
- Chemical Effects of Electric Current class 8 Notes Science
- Some Natural Phenomena class 8 Notes Science
- Light class 8 Notes Science
- Stars and the Solar System class 8 Notes Science
- Pollution of Air and Water class 8 Notes Science