Topics
Matter in Our Surroundings
- Matter
- Characteristics of Molecules of Matter
- The Solid State
- The Liquid State
- The Gaseous State
- Plasma
- Bose-einstein Condensate
- Change of State of Matter
- Concept of Melting (Fusion)
- Concept of Boiling (Vaporization)
- Concept of Sublimation
- Concept of Freezing (Solidification)
- Concept of Condensation (Liquefaction)
- Concept of Desublimation (Deposition)
- Concept of Evaporation
Is Matter Around Us Pure
- Matter
- Concept of Mixture
- Concept of Solution
- Concentration of a Solution
- Concept of Suspension
- Concept of Colloidal Solution
- Evaporation Method
- Centrifugation Method
- Using a Separating Funnel Method
- Sublimation Method
- Chromatography Method
- Distillation Method
- Fractional Distillation Method
- Crystallisation Method
- Concept of Physical Changes
- Types of Pure Substances
- Concept of Elements
- Concept of Compounds
Atoms and Molecules
- Introduction of Atoms and Molecules
- Law of Conservation of Mass
- Law of Constant Proportions
- Concept of Atom
- The Modern Day Symbols of Atoms of Different Elements
- Concept of Atomic Mass
- Concept of Molecule
- Molecules of Elements
- Molecules of Compounds
- Concept of an Ion
- Writing Chemical Formulae
- Concept of Molecular Mass
- Concept of Molecular Mass
- Mole Concept
- Atoms and Molecules Numericals
Structure of the Atom
- Concept of Atom
- Charged Particles in Matter
- The Structure of an Atom
- J. J. Thomson’s Model of an Atom
- Rutherford’s Model of an Atom
- Neil Bohr’s Model of Atom
- Concept of Proton
- Concept of Neutrons
- Concept of Electron
- Concept of Electrons Distributed in Different Orbits (Shells)
- Concept of Valency
- Concept of Atomic Number
- Concept of Mass Number
- Concept of Isotopes
- Concept of Isobars
- Structure of Atom Numericals
The Fundamental Unit of Life
- The Invention of the Microscope and the Discovery of Cell
- Prokaryotic and Eukaryotic Cell
- Osmosis and Osmotic Pressure
- Structure of a Cell
- Plasma Membrane Or Cell Membrane
- Cell Wall
- Nucleus
- Cytoplasm
- Endoplasmic Reticulum (Er)
- Golgi Apparatus
- Lysosomes
- Mitochondria
- Plastids
- Vacuoles
- Difference Between Plant Cell and Animal Cell
- Cell Inclusion
Tissues
Diversity in Living Organisms
Motion
- Concept of Motion
- Displacement
- Concept of Motion
- Motion Along a Straight Line
- Uniform Motion and Non-uniform Motion
- Measuring the Rate of Motion - Speed with Direction
- Rate of Change of Velocity
- Graphical Representation of Motion: Distance - Time Graphs
- Graphical Representation of Motion: Distance - Time Graphs
- Graphical Representation of Motion: Velocity - Time Graphs
- Equations of Motion by Graphical Method
- Derivation of Velocity - Time Relation by Graphical Method
- Derivation of Position - Time Relation by Graphical Method
- Derivation of Position - Velocity Relation by Graphical Method
- Uniform Circular Motion
- Motion (Numerical)
Force and Laws of Motion
- Force
- Force - Push Or Pull
- Forces Are Due to an Interaction
- Exploring Forces
- Force Can Change the State of Motion
- Force Can Change the Shape of an Object
- Concept of Contact Forces
- Concept of Non-contact Forces
- Balanced and Unbalanced Forces
- Newton's First Law of Motion
- Inertia and Mass
- Newton's Second Law of Motion
- Newton's Third Law of Motion
- Conservation of Momentum
- Force and Laws of Motion (Numerical)
Gravitation
- Concept of Gravitation
- Newton’s Universal Law of Gravitation
- Free Fall
- To Calculate the Value of G
- Motion of Objects Under the Influence of Gravitational Force of the Earth
- Concept of Mass
- Concept of Weight
- Pressure
- Buoyancy Force
- Pressure Exerted by Liquids and Gases
- Density of the Fluid
- Archimedes' Principle
- Relative Density
Work and Energy
- Work
- Work Done by a Constant Force
- Energy
- Different Forms of Energy
- Kinetic Energy
- Potential Energy
- The Potential Energy of an Object at a Height
- Work Done by a Energy
- Work Done by a Power
- Conversion of Energy from One Form to Another
- Law of Conservation of Energy
- Rate of Doing Work
- Energy
- Work and Energy (Numericals)
Sound
- Sound
- Production of Sound
- Propagation of Sound
- Sound Need a Medium to Travel
- Longitudinal Nature of Sound Waves
- Characteristics of a Sound Wave
- Speed of Sound
- Reflection of Sound
- Reflection of Sound – Echo
- Reflection of Sound – Reverberation
- Reflection of Sound
- Range of Hearing in Humans
- SONAR
- Structure of the Human Ear (Auditory Aspect Only)
- Sound (Numerical)
Why Do We Fall ill
- Health and Its Failure
- The Significance of ‘Health'
- Personal and Community Issues Both Matter for Health
- Distinctions Between ‘Healthy’ and ‘Disease-free’
- Identification of Disease
- Categories of Diseases
- Chronic Diseases and Poor Health
- Causes of Disease
- Infectious and Non-infectious Causes
- Categories of Diseases
- Infectious Agents
- Diseases Caused by Bacteria
- Diseases Caused by Parasitic Worms: Taeniasis
- Diseases Caused by Protozoa
- Modes of Transmission of Diseases (Air, Water, Food, Insects)
- Organ-specific and Tissue-specific Manifestations of Disease
- Principles of Prevention of Diseases
- Principles of Treatment of Diseases
Our Environment
- Introduction of Our Environment
- The Breath of Life - Air
- The Role of the Atmosphere in Climate Control
- Movements of Air (Winds) and Its Role in Bringing Rains Across India
- Water - A Wonder Liquid
- Concept of Water Pollution
- Mineral Riches in the Soil
- Biogeochemical Cycle
- The Water-cycle
- The Nitrogen-cycle
- The Carbon Cycle
- The Oxygen-cycle
- Ozone Layer Depletion
Improvement in Food Resources
notes
POTENTIAL ENERGY OF AN OBJECT AT A HEIGHT:
An object increases its energy when raised through a height. This is because work is done on it against gravity while it is being raised. The energy present in such an object is the gravitational potential energy. The gravitational potential energy of an object at a point above the ground is defined as the work done in raising it from the ground to that point against gravity. It is easy to arrive at an expression for the gravitational potential energy of an object at a height.
Consider an object of mass, m. Let it be raised through a height, h from the ground. A force is required to do this. The minimum force required to raise the object is equal to the weight of the object, mg. The object gains energy equal to the work done on it. Let the work done on the object against gravity be W. That is, work done, W = force × displacement = mg × h = mgh Since work done on the object is equal to mgh, an energy equal to mgh units is gained by the object. This is the potential energy (EP) of the object. Ep = mgh
It is useful to note that the work done by gravity depends on the difference in vertical heights of the initial and final positions of the object and not on the path along which the object is moved.
The block is raised from position A to B by taking two different paths. Let the height AB = h. In both the situations the work done on the object is mgh.
notes
Potential Energy:
Every object possesses some energy called Potential Energy. An object when gains energy may store it in itself as potential energy.
We know that when an object rises above the ground some work is done against gravity. Since work is done on the object, the object would gain some energy. The energy that the object gains at a height is called Gravitational Potential Energy. It is defined as the amount of work done required in raising an object above the ground up to a certain point against the gravity.
W = F x d = F x h (height)
And F = m x g (because the force is applied against gravity)
So, W = m x g x h
Hence potential energy of object A, Ep = m x g x h
Elastic Potential energy: Same work has to be done to change the shape of a body. This work gets stored in the deformed body in the form of elastic potential energy. Elastic potential energy is never negative whether due to extension or to compression.
text
- Potential Energy
- Forms of Potential Energy
- Some Examples of Potential Energy
- Expression for the Gravitational Potential Energy
