Class 11th

Temperature and heat * Heat is defined as a form of energy that flows from hotter body to a colder body when they are in thermal contact. * When two bodies are in thermal contact and there is no net exchange of heat, then they are said to be in thermal equilibrium. * The physical ... Read more

Physical quantities –fluids * A fluid is any matter that has tendency to flow. All liquids and gases are together referred to as fluids. * External force acting per unit area on a solid is called stress. * Pressure is defined as force exerted per unit area. * Density of a fluid is the ration ... Read more

Elastic behaviour of solids * When a force acts on a body, it accelerates in the direction of the net force. * When a set of equal and opposite forces acts on a body, there is no net force on the body but it gets deformed, changing its size or shape or both. * The ... Read more

Kepler’s Law of Gravitation * To resolve shortcomings of the models propounded by Ptolemy and Copernicus, * Kepler propounded three laws on planetary motion. * Kepler’s first law, the law of orbits, states that the orbit of a planet is an ellipse with the sun at one of the foci. * An ellipse is a ... Read more

Rigid Body * A rigid body is a ‘system of particles’ with a finite size that do not get deformed under the influence of any external force. * The distance between ant two particles of an ideal rigid body does not change even when it is under the influence of external forces. * The motion ... Read more

Work Energy Theorem * The dot product of two vectors is equal to the product of the magnitude of the two vectors and cosine of the angle between the two vectors. The result of a dot product is always scalar. * Using the dot product, the work done is measured as the dot product of ... Read more

* Kinetics is the study of the displacement, velocity and acceleration of a body in motion along with the forces responsible for the motion. * A force applied by an external agency either accelerates or retards a body. * The tendency of a body moving with uniform velocity in a straight line to stay in ... Read more

Scalars and vectors * Rectilinear motion is motion that occurs in a straight line. * Entities that are described completely with the help of a number along with its unit are called scalars * A number along with the unit that represents the measure of a physical quantity is called its magnitude. * Mass, distance, ... Read more