Topics
Matter in Our Surroundings
- Matter
- Characteristics of Particles (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
- Mixture
- Solutions
- Concentration of a Solution
- Concept of Suspension
- Colloidal Solution
- Evaporation Method
- Centrifugation Method
- Solvent Extraction (Using a Separating Funnel Method)
- Sublimation Method
- Chromatography Method
- Distillation Method
- Fractional Distillation Method
- Crystallisation Method
- Classification of Change: Physical Changes
- Pure Substances
- Elements
- Compound
Atoms and Molecules
- Difference Between Atoms and Molecules
- Law of Conservation of Mass
- Law of Constant Proportions
- Atom
- The Modern Day Symbols of Atoms of Different Elements
- Mass Number (A) or Atomic Mass
- Molecules
- 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
- Atom
- Sub-atomic Particles of Atom
- Structure of an Atom
- J. J. Thomson’s Atomic model
- Lord Rutherford’s Atomic model
- Neil Bohr’s Model of Atom
- Concept of Proton
- Neutrons (N)
- Concept of Electron
- Concept of Electrons Distributed in Different Orbits (Shells)
- Valency and Its Types
- Atomic Number (Z)
- Mass Number (A) or Atomic Mass
- Isotopes
- Isobars
- Atoms and Molecules 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
- Cell Wall - “Supporter and Protector”
- Nucleus - “Brain” of the Cell
- Cytoplasm - “Area of Movement”
- Endoplasmic Reticulum (ER)
- Golgi Apparatus
- Lysosome - “Suicidal Bag”
- Mitochondria - “Power House of the Cell”
- Plastids
- Non-living Substances Or Cell Inclusions
- Difference Between Plant Cell and Animal Cell
- Cell Inclusion
Tissues
Diversity in Living Organisms
Motion
- Motion and Rest
- Distance and Displacement
- Motion and Rest
- Motion Along a Straight Line
- Types of Motion Based on Speed
- Measuring the Rate of Motion - Speed with Direction
- Rate of Change of Velocity
- Distance - Time Graphs
- Distance - Time Graphs
- 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
- Types of Motion Based on Speed
- Motion (Numerical)
Force and Laws of Motion
- Force
- Force - Push or Pull
- Force - Push or Pull
- Force - Push or Pull
- Effect of Force
- Effect of Force
- Types of Force: Contact Force
- Types of Force: Non-Contact Force
- 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
- Trust and Pressure
- Buoyancy Force (Upthrust Force)
- Pressure Exerted by Liquids and Gases
- Density of the Fluid
- Archimedes' Principle
- Relative Density
Work and Energy
- Definition of Work
- Work Done by a Constant Force
- Concept of Energy
- Different Forms of Energy
- Types of Mechanical Energy: Kinetic Energy
- Types of Mechanical Energy: Potential Energy
- The Potential Energy of an Object at a Height
- Work Done by a Energy
- Work Done by a Power
- Conversion of One Form of Energy into the Other Form
- Law of Conservation of Energy
- Rate of Doing Work
- Concept of Energy
- Work and Energy (Numericals)
Sound
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
- Airborne Diseases Caused by Bacteria
- Diseases Caused by Parasitic Worms
- 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
- The 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
- 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
Second Law of Motion
“The rate of change of momentum of an object is proportional to the applied unbalanced force in the direction of the force.”
This law of motion is also called the Law of Force and Acceleration. It means that force is equal to the change in momentum per change in time. For a constant mass, force equals mass times acceleration.
notes
MATHEMATICAL FORMULATION OF SECOND LAW OF MOTION
Suppose an object of mass, m is moving along a straight line with an initial velocity, u. It is uniformly accelerated to velocity, v in time, t by the application of a constant force, F throughout the time, t. The initial and final momentum of the object will be, p1 = mu and p2 = mv respectively.
The change in momentum
∝ p2 – p1
∝ mv – mu
∝ m × (v – u).
The rate of change of momentum ∝ `"m" xx "(v - u)"/"t"`
or, the applied force,
`"F" ∝ "m"xx"(v - u)" / "t"`
`"F" ∝ "km"xx"(v - u)" / "t"`
=kma
Here a = [(v – u)/t] is the acceleration, which is the rate of change of velocity. The quantity, k is a constant of proportionality.
The SI units of mass and acceleration are kg and m/s2 respectively.
The unit of force is so chosen that the value of the constant, k becomes one. For this, one unit of force is defined as the amount that produces an acceleration of 1 m/s2 in an object of 1 kg mass.
That is,
1 unit of force = k × (1 kg) × (1 m/s2).
Thus, the value of k becomes 1.
F = ma
The unit of force is kg m s-2 or newton, which has the symbol N. The second law of motion gives us a method to measure the force acting on an object as a product of its mass and acceleration.
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Related QuestionsVIEW ALL [22]
The following is the distance-time table of an object in motion:-
| Time in seconds | Distance in metres |
| 0 | 0 |
| 1 | 1 |
| 2 | 8 |
| 3 | 27 |
| 4 | 64 |
| 5 | 125 |
| 6 | 216 |
| 7 | 343 |
(a) What conclusion can you draw about the acceleration? Is it constant, increasing, decreasing, or zero?
(b)What do you infer about the forces acting on the object?
