Friction Notes for Class 8

 Friction is the resistance that any object encounters as it moves across or through a surface or another medium. Without frictional force, an object would either not start moving or, if it was already moving, then not stop. The notes for Class 8 Science Chapter 12 go into detail into the numerous facets of friction that we encounter every day. Students can access free CBSE Solutions (NCERT) and other study materials on the platform Sarthak. If you're a math student looking for better answers, you can download the Class 8 MathsNCERT Solutions to help you review the entire syllabus and do better on test day.

Important topics Covered in Friction Notes for Class 8:

·         Introduction

·         Friction

·         Factors affecting friction

·         Friction: A Necessary Evil

·         Increasing and reducing friction

·         Fluid Friction

·         Rolling Friction

·         Sliding Friction

Static Friction Introduction:

·         In our day-to-day life, we see several situations which use application of friction.

·         A vehicle slows down when a brake is applied.

·         A ball rolling on the ground stops after sometime.

·         The tire of vehicle wears down after its regular usage.

·         These are some applications of friction.

Friction:

·         When one surface is moving over another surface, a force which opposes the relative motion between the two is called friction.

·         The force of friction always opposes the force applied to it.

·         There will be no friction if there is no contact between the surfaces.

Factors affecting

·         The irregularities of the two contact surfaces are the cause of friction.

·         No surface is perfectly smooth in this universe.

·         Even some surfaces that look smooth to our naked eye actually look rough or bumpy when we see it under a microscope.

·         Smooth surfaces cause lesser friction whereas rough surfaces cause greater friction.

·         If the force applied is more, greater will be the friction.

·         Greater is the mass of object greater will be the friction.

·         The force of sliding friction is always less than static friction. Rolling friction is less than sliding friction.

Friction: A Necessary Evil

·         Some disadvantage of frictions is given by:

·         More heat energy is dissipated from engine due to friction between surfaces in motion.

·         A large amount of energy is lost in pulling objects on a rough surface.

·         Shoes soles and tires wear after usage.

·         It causes moving objects to stop or slow down.

·         It also causes wear and tear of moving machinery parts.