Study point

This article brings you the CBSE Class 9 Science notes on chapter 1 'Matter in Our Surroundings'. These chapter notes are prepared by the subject experts and cover every important topic from the chapter. In between these notes, exercise questions are provided. Students must solve these questions to test their understanding about the learned topics. These questions will help you to track your preparation level and get a hold on the subject. Main topics covered in CBSE Class 9 Science,  Matter in Our Surroundings: Capter Notes, are: • Matter, its definition and caracteristics • Diffusion and its Applications • Brownian Motion • States of Matter • Interconversion of Three States of Matter • Evaporation • Important physical quantities and their SI units Also Check: CBSE Class 9 Complete Study Material for 2020-21 Key notes for Chapter- Matter in Our Surroundings, are: Matter: • Anything that occupies space and has mass is called matter. • It exists in the form of

<!-- End Google Tag Manager -- Basic  principals of physics   We start from the following five basic principles to construct all other physical laws and equations. These five basic principles are: (1) Constituent principle: the basic constituents of matter are various kinds of identical particles. This can also be called locality principle; (2) Causality principle: the future state depends only on the present state; (3) Covariance principle: the physics should be invariant under an arbitrary coordinate transformation; (4) Invariance or Symmetry principle: the spacetime is homogeneous; (5) Equi-probability principle: all the states in an isolated system are expected to be occupied with equal probability. These five basic principles can be considered as physical common senses. It is very natural to have these basic principles. More important is that these five basic principles are consistent with one another. From these five principles, we derive a vast set of equations which expl

What is physics? ArticleMediaAdditional Info HomeSciencePhysics Physics science Cite Share More WRITTEN BY Laurie M. Brown See All Contributors Emeritus Professor of Physics and Astronomy, Northwestern University, Evanston, Illinois. Coeditor of The Birth of Particle Physics. See Article History Physics, science that deals with the structure of matter and the interactions between the fundamental constituents of the observable universe. In the broadest sense, physics (from the Greek physikos) is concerned with all aspects of nature on both the macroscopic and submicroscopic levels. Its scope of study encompasses not only the behaviour of objects under the action of given forces but also the nature and origin of gravitational, electromagnetic, and nuclear force fields. Its ultimate objective is the formulation of a few comprehensive principles that bring together and explain all such disparate phenomena.   Bernoulli model of gas pressure As conceived by Daniel Bernoulli in Hydrodynamica

Multiple Images with Plane Mirrors Introduction The number of images formed by two adjacent plane mirrors depends on the angle between the mirror. If  θ  (in degrees) is angle between the plane mirrors then number of images are given by, n=n = 360 θ − 1. We verify this formula in this experiment. Apparatus Two plane mirrors, protractor to measure angle, candle, matchbox. Procedure Take two plane mirrors (without frame). Place both the mirrors side by side and fix the junction where they meet with a cello tape. Now you will be able to open and close the mirrors like a book. Place both the mirrors at a small angle apart in the upright position on the floor. Place a lighted candle in the space between the two mirrors. You will observe many images of the candle which makes a beautiful scene. Now, by gradually decreasing the angle between the mirrors observe the images being formed. You will now observe more and more numbers of images of the candle. Similarly, if the angle between the mirro