SlideShare uma empresa Scribd logo
1 de 18
Baixar para ler offline
+




    Force
+
    FORCE
   Force: is either a push or a pull that acts on an object.

   Whenever you bend, twist, stretch or compress something you are
    using a pushing or pulling force.

   Force is an effect which can,

   Start motion,

   Stop motion,

   Change the speed or direction of motion,

   Change the shape or size of a body.
+
    Unit of Force

       Force is represented by the symbol F and is measured in
        Newton (N).The pull of the Earth on a 100 g mass is about 1 N.
+
    Measuring Force


        The force is measured by a spring balance or
         dynamometer.
+
    Action and Reaction


   For every action force, there is always an equal but opposite reaction
    force. If an object applies a force on a second object, then the second
    object will exert an equal but opposite force on the first object.
+
    TYPES OF FORCE


   There are many different kinds of forces:

   Gravitational force

   Magnetic force

   Electrostatic force

   Tension

   Frictional force
+
    Gravitational Force and Weight

       Gravitational Force: The force of attraction between two
        objects due to their masses

       Gravitational force depends on;

       The masses of the objects,

       The distance between them.
+
    Gravitational Force and Weight


     Gravitational  force is directly proportional to the
      product of the masses: The greater the masses the
      greater the gravitational force.
     Gravitational force is inversely proportional to the
      distance between the masses: The larger the distance
      between the objects the smaller the gravitational force.

     The   pull of the earth on a 1 kg mass is about 10 N
+
    Weight


   Weight (w): The gravitational force acting on an object. Since it is a
    force it is measured by a spring scale and its unit is Newton (N).
+
    How does weight change?

     The  weight of an object on the earth depends on its
      distance from the earth's centre.
     Near the earth, an object of mass 1 kg has a weight of
      about 10 N, whereas 22 000 km away from the centre of
      the earth, the weight of the object reduces to 1 N.
     The weight of an object of 1kg weighs most at the poles
      (9.83 N) and least at the equator (9.78 N). A body having
      a weight of 600 N at the equator would have a weight of
      603 N at the poles
+
    How does weight change?
+
    How does weight change?


   The weight of an object
    also changes from one
    planet to another since g
    is different for different
    planets. However the
    mass of the object is the
    same in all planets.
+


                 MASS                        WEIGHT

    It is the amount of matter    It is the gravitational force
    contained in substance        acting on an object

    It is the same everywhere     It changes from place to place

    It is measured by equal arm
                                  It is measured by spring scale
    balance

    Its unit is kg                Its unit is N

    It is a scalar quantity       It is a vector quantity
+
    MAGNETIC FORCE

       Magnetic Force is the attractive or repulsive force between the
        poles of two magnets.




        Unlike poles attract each           Like poles repel each
        other (a)                           other (b)
+
    ELECTROSTATIC FORCE

       Electrostatic Force is the attractive or repulsive force among
        electrically charged objects or electric charges such as
        electrons and protons.
+
    TENSION

       Tension (T): It is the pulling force in a rope or a chain.
+
    FRICTIONAL FORCE

 Frictional     force: It is an important force which only acts
    when two objects are touching and are applying force to
    one another.
     It is a force that slows down moving objects and brings
      them to rest.
     It always acts in a direction opposite to the direction of the
      force applied to the object.
     Walking is possible only on a frictional surface.
     Water also applies a frictional force to the objects moving
      in it.
     Frictional force does not depend on the area of the
      rubbing surfaces.
+
       The frictional force between the object and the table
        depends on two factors;

         a) The weight of the object.

b) The roughness of the surfaces rubbing together.

Mais conteúdo relacionado

Mais procurados

Mass, weight and density
Mass, weight and densityMass, weight and density
Mass, weight and densityjs_audrey
 
Gravity mass weight
Gravity mass weightGravity mass weight
Gravity mass weightiesbscience
 
Unit 4: Forces and their effects
Unit 4: Forces and their effectsUnit 4: Forces and their effects
Unit 4: Forces and their effectsMónica
 
2.5 the effects of a force edit
2.5 the effects of a force edit2.5 the effects of a force edit
2.5 the effects of a force editsteadygirl
 
Forces in action (grade 6)
Forces in action (grade 6)Forces in action (grade 6)
Forces in action (grade 6)Yoshy Faweta
 
Newton’s law of gravitation
Newton’s law of gravitationNewton’s law of gravitation
Newton’s law of gravitationChelsea Shi
 
NA - Mass Weight Density - E-Learning
NA - Mass Weight Density - E-LearningNA - Mass Weight Density - E-Learning
NA - Mass Weight Density - E-Learningharrywwh
 
Law Of Gravitation PPT For All The Students | With Modern Animations and Info...
Law Of Gravitation PPT For All The Students | With Modern Animations and Info...Law Of Gravitation PPT For All The Students | With Modern Animations and Info...
Law Of Gravitation PPT For All The Students | With Modern Animations and Info...Jay Butani
 
Newton’s universal law of gravitation
Newton’s universal  law of gravitationNewton’s universal  law of gravitation
Newton’s universal law of gravitationVineetha Vijayan
 
6th Grade Chapter 10- forces and motion
6th Grade  Chapter 10- forces and motion6th Grade  Chapter 10- forces and motion
6th Grade Chapter 10- forces and motionSteven_iannuccilli
 
Mass and weight
Mass and weightMass and weight
Mass and weightjoverba
 

Mais procurados (19)

Mass, weight and density
Mass, weight and densityMass, weight and density
Mass, weight and density
 
Gravity mass weight
Gravity mass weightGravity mass weight
Gravity mass weight
 
Forces Ppt
Forces PptForces Ppt
Forces Ppt
 
Unit 4: Forces and their effects
Unit 4: Forces and their effectsUnit 4: Forces and their effects
Unit 4: Forces and their effects
 
2.5 the effects of a force edit
2.5 the effects of a force edit2.5 the effects of a force edit
2.5 the effects of a force edit
 
Nature of forces
Nature of forcesNature of forces
Nature of forces
 
Mass, weight
Mass, weightMass, weight
Mass, weight
 
Forces
ForcesForces
Forces
 
Forces in action (grade 6)
Forces in action (grade 6)Forces in action (grade 6)
Forces in action (grade 6)
 
What Is Force
What Is ForceWhat Is Force
What Is Force
 
Newton’s law of gravitation
Newton’s law of gravitationNewton’s law of gravitation
Newton’s law of gravitation
 
NA - Mass Weight Density - E-Learning
NA - Mass Weight Density - E-LearningNA - Mass Weight Density - E-Learning
NA - Mass Weight Density - E-Learning
 
Law Of Gravitation PPT For All The Students | With Modern Animations and Info...
Law Of Gravitation PPT For All The Students | With Modern Animations and Info...Law Of Gravitation PPT For All The Students | With Modern Animations and Info...
Law Of Gravitation PPT For All The Students | With Modern Animations and Info...
 
Newton’s universal law of gravitation
Newton’s universal  law of gravitationNewton’s universal  law of gravitation
Newton’s universal law of gravitation
 
Types of forces
Types of forcesTypes of forces
Types of forces
 
6th Grade Chapter 10- forces and motion
6th Grade  Chapter 10- forces and motion6th Grade  Chapter 10- forces and motion
6th Grade Chapter 10- forces and motion
 
Gravity Form 4
Gravity Form 4Gravity Form 4
Gravity Form 4
 
Mass and weight
Mass and weightMass and weight
Mass and weight
 
Newton's Laws & Gravitation
Newton's Laws & GravitationNewton's Laws & Gravitation
Newton's Laws & Gravitation
 

Destaque (7)

After school activity ks3
After school activity ks3After school activity ks3
After school activity ks3
 
Force
ForceForce
Force
 
Multichoice Quiz on Forces KS3
Multichoice Quiz on Forces KS3 Multichoice Quiz on Forces KS3
Multichoice Quiz on Forces KS3
 
Unit 7
Unit 7Unit 7
Unit 7
 
Force push or pull 2
Force push or pull 2Force push or pull 2
Force push or pull 2
 
Force.Ppt
Force.PptForce.Ppt
Force.Ppt
 
All about Forces
All about ForcesAll about Forces
All about Forces
 

Semelhante a Force

Forces and their effects pps
Forces and their effects ppsForces and their effects pps
Forces and their effects ppsTeacher Tanoto
 
Ppt Gravity
Ppt GravityPpt Gravity
Ppt Gravityffiala
 
Ch.14.forces and motion (week 2)
Ch.14.forces and motion (week 2)Ch.14.forces and motion (week 2)
Ch.14.forces and motion (week 2)Reem Bakr
 
The nature of force
The nature of forceThe nature of force
The nature of forceMarvin Agner
 
Class 9 chapter 10 Gravitation
Class 9 chapter 10 Gravitation Class 9 chapter 10 Gravitation
Class 9 chapter 10 Gravitation Prachi Mishra
 
Massweightanddensity 130828084525-phpapp01
Massweightanddensity 130828084525-phpapp01Massweightanddensity 130828084525-phpapp01
Massweightanddensity 130828084525-phpapp01sylvia flores
 
Forces and their effects
Forces and their effectsForces and their effects
Forces and their effectsMuhammadIb1
 
ENERGY AND CHANGE GRADE 9.pptx
ENERGY AND CHANGE GRADE 9.pptxENERGY AND CHANGE GRADE 9.pptx
ENERGY AND CHANGE GRADE 9.pptxSinethemba Ramadje
 
3 equilibrium of concurrent forces and
3 equilibrium  of  concurrent  forces   and3 equilibrium  of  concurrent  forces   and
3 equilibrium of concurrent forces andfelna00
 
force and motion.pdf
force and motion.pdfforce and motion.pdf
force and motion.pdfmayann29
 

Semelhante a Force (20)

Force
ForceForce
Force
 
8374232.ppt
8374232.ppt8374232.ppt
8374232.ppt
 
FORCE-1.pptx
FORCE-1.pptxFORCE-1.pptx
FORCE-1.pptx
 
Forces and their effects pps
Forces and their effects ppsForces and their effects pps
Forces and their effects pps
 
Ppt Gravity
Ppt GravityPpt Gravity
Ppt Gravity
 
Newton's Laws
Newton's LawsNewton's Laws
Newton's Laws
 
Ch.14.forces and motion (week 2)
Ch.14.forces and motion (week 2)Ch.14.forces and motion (week 2)
Ch.14.forces and motion (week 2)
 
Force and pressure
Force and pressureForce and pressure
Force and pressure
 
gravitation.pptx
gravitation.pptxgravitation.pptx
gravitation.pptx
 
The nature of force
The nature of forceThe nature of force
The nature of force
 
Class 9 chapter 10 Gravitation
Class 9 chapter 10 Gravitation Class 9 chapter 10 Gravitation
Class 9 chapter 10 Gravitation
 
Forces
ForcesForces
Forces
 
Massweightanddensity 130828084525-phpapp01
Massweightanddensity 130828084525-phpapp01Massweightanddensity 130828084525-phpapp01
Massweightanddensity 130828084525-phpapp01
 
Forces and their effects
Forces and their effectsForces and their effects
Forces and their effects
 
Forces
ForcesForces
Forces
 
Unit 3 Forces.ppt
Unit 3 Forces.pptUnit 3 Forces.ppt
Unit 3 Forces.ppt
 
ENERGY AND CHANGE GRADE 9.pptx
ENERGY AND CHANGE GRADE 9.pptxENERGY AND CHANGE GRADE 9.pptx
ENERGY AND CHANGE GRADE 9.pptx
 
3 equilibrium of concurrent forces and
3 equilibrium  of  concurrent  forces   and3 equilibrium  of  concurrent  forces   and
3 equilibrium of concurrent forces and
 
Force and Motion- Sci. 8
Force and Motion- Sci. 8Force and Motion- Sci. 8
Force and Motion- Sci. 8
 
force and motion.pdf
force and motion.pdfforce and motion.pdf
force and motion.pdf
 

Mais de mstf mstf

Trigonometry by mstfdemirdag
Trigonometry by mstfdemirdagTrigonometry by mstfdemirdag
Trigonometry by mstfdemirdagmstf mstf
 
Functions by mstfdemirdag
Functions by mstfdemirdagFunctions by mstfdemirdag
Functions by mstfdemirdagmstf mstf
 
Trigonometric functions
Trigonometric functionsTrigonometric functions
Trigonometric functionsmstf mstf
 
Quadratic functions
Quadratic functionsQuadratic functions
Quadratic functionsmstf mstf
 
Sequences and series
Sequences and seriesSequences and series
Sequences and seriesmstf mstf
 
Pre geometry
Pre geometryPre geometry
Pre geometrymstf mstf
 
Solving linear equations in two
Solving linear equations in twoSolving linear equations in two
Solving linear equations in twomstf mstf
 
Natural numbers
Natural numbersNatural numbers
Natural numbersmstf mstf
 
Divisibility
DivisibilityDivisibility
Divisibilitymstf mstf
 
Prime numbers and factorization
Prime numbers and factorizationPrime numbers and factorization
Prime numbers and factorizationmstf mstf
 
Motion in two dimensions
Motion in two dimensionsMotion in two dimensions
Motion in two dimensionsmstf mstf
 
Relative motion
Relative motionRelative motion
Relative motionmstf mstf
 

Mais de mstf mstf (20)

Trigonometry by mstfdemirdag
Trigonometry by mstfdemirdagTrigonometry by mstfdemirdag
Trigonometry by mstfdemirdag
 
Functions by mstfdemirdag
Functions by mstfdemirdagFunctions by mstfdemirdag
Functions by mstfdemirdag
 
Trigonometric functions
Trigonometric functionsTrigonometric functions
Trigonometric functions
 
Quadratic functions
Quadratic functionsQuadratic functions
Quadratic functions
 
Sequences and series
Sequences and seriesSequences and series
Sequences and series
 
Functions
FunctionsFunctions
Functions
 
Pre geometry
Pre geometryPre geometry
Pre geometry
 
Solving linear equations in two
Solving linear equations in twoSolving linear equations in two
Solving linear equations in two
 
Natural numbers
Natural numbersNatural numbers
Natural numbers
 
Logic
LogicLogic
Logic
 
Density
DensityDensity
Density
 
Mechanics
MechanicsMechanics
Mechanics
 
Divisibility
DivisibilityDivisibility
Divisibility
 
Free fall
Free fallFree fall
Free fall
 
Prime numbers and factorization
Prime numbers and factorizationPrime numbers and factorization
Prime numbers and factorization
 
Exponents
ExponentsExponents
Exponents
 
Motion in two dimensions
Motion in two dimensionsMotion in two dimensions
Motion in two dimensions
 
Radicals
RadicalsRadicals
Radicals
 
Fractions
FractionsFractions
Fractions
 
Relative motion
Relative motionRelative motion
Relative motion
 

Último

Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...
Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...
Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...Will Schroeder
 
Secure your environment with UiPath and CyberArk technologies - Session 1
Secure your environment with UiPath and CyberArk technologies - Session 1Secure your environment with UiPath and CyberArk technologies - Session 1
Secure your environment with UiPath and CyberArk technologies - Session 1DianaGray10
 
9 Steps For Building Winning Founding Team
9 Steps For Building Winning Founding Team9 Steps For Building Winning Founding Team
9 Steps For Building Winning Founding TeamAdam Moalla
 
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdfIaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdfDaniel Santiago Silva Capera
 
Bird eye's view on Camunda open source ecosystem
Bird eye's view on Camunda open source ecosystemBird eye's view on Camunda open source ecosystem
Bird eye's view on Camunda open source ecosystemAsko Soukka
 
Empowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership BlueprintEmpowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership BlueprintMahmoud Rabie
 
Introduction to Matsuo Laboratory (ENG).pptx
Introduction to Matsuo Laboratory (ENG).pptxIntroduction to Matsuo Laboratory (ENG).pptx
Introduction to Matsuo Laboratory (ENG).pptxMatsuo Lab
 
activity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdf
activity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdf
activity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdfJamie (Taka) Wang
 
Meet the new FSP 3000 M-Flex800™
Meet the new FSP 3000 M-Flex800™Meet the new FSP 3000 M-Flex800™
Meet the new FSP 3000 M-Flex800™Adtran
 
Artificial Intelligence & SEO Trends for 2024
Artificial Intelligence & SEO Trends for 2024Artificial Intelligence & SEO Trends for 2024
Artificial Intelligence & SEO Trends for 2024D Cloud Solutions
 
Videogame localization & technology_ how to enhance the power of translation.pdf
Videogame localization & technology_ how to enhance the power of translation.pdfVideogame localization & technology_ how to enhance the power of translation.pdf
Videogame localization & technology_ how to enhance the power of translation.pdfinfogdgmi
 
Building AI-Driven Apps Using Semantic Kernel.pptx
Building AI-Driven Apps Using Semantic Kernel.pptxBuilding AI-Driven Apps Using Semantic Kernel.pptx
Building AI-Driven Apps Using Semantic Kernel.pptxUdaiappa Ramachandran
 
Building Your Own AI Instance (TBLC AI )
Building Your Own AI Instance (TBLC AI )Building Your Own AI Instance (TBLC AI )
Building Your Own AI Instance (TBLC AI )Brian Pichman
 
UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6DianaGray10
 
Cybersecurity Workshop #1.pptx
Cybersecurity Workshop #1.pptxCybersecurity Workshop #1.pptx
Cybersecurity Workshop #1.pptxGDSC PJATK
 
UiPath Studio Web workshop series - Day 7
UiPath Studio Web workshop series - Day 7UiPath Studio Web workshop series - Day 7
UiPath Studio Web workshop series - Day 7DianaGray10
 
Computer 10: Lesson 10 - Online Crimes and Hazards
Computer 10: Lesson 10 - Online Crimes and HazardsComputer 10: Lesson 10 - Online Crimes and Hazards
Computer 10: Lesson 10 - Online Crimes and HazardsSeth Reyes
 
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDEADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDELiveplex
 
Designing A Time bound resource download URL
Designing A Time bound resource download URLDesigning A Time bound resource download URL
Designing A Time bound resource download URLRuncy Oommen
 

Último (20)

Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...
Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...
Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...
 
Secure your environment with UiPath and CyberArk technologies - Session 1
Secure your environment with UiPath and CyberArk technologies - Session 1Secure your environment with UiPath and CyberArk technologies - Session 1
Secure your environment with UiPath and CyberArk technologies - Session 1
 
9 Steps For Building Winning Founding Team
9 Steps For Building Winning Founding Team9 Steps For Building Winning Founding Team
9 Steps For Building Winning Founding Team
 
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdfIaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
 
Bird eye's view on Camunda open source ecosystem
Bird eye's view on Camunda open source ecosystemBird eye's view on Camunda open source ecosystem
Bird eye's view on Camunda open source ecosystem
 
Empowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership BlueprintEmpowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership Blueprint
 
Introduction to Matsuo Laboratory (ENG).pptx
Introduction to Matsuo Laboratory (ENG).pptxIntroduction to Matsuo Laboratory (ENG).pptx
Introduction to Matsuo Laboratory (ENG).pptx
 
201610817 - edge part1
201610817 - edge part1201610817 - edge part1
201610817 - edge part1
 
activity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdf
activity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdf
activity_diagram_combine_v4_20190827.pdfactivity_diagram_combine_v4_20190827.pdf
 
Meet the new FSP 3000 M-Flex800™
Meet the new FSP 3000 M-Flex800™Meet the new FSP 3000 M-Flex800™
Meet the new FSP 3000 M-Flex800™
 
Artificial Intelligence & SEO Trends for 2024
Artificial Intelligence & SEO Trends for 2024Artificial Intelligence & SEO Trends for 2024
Artificial Intelligence & SEO Trends for 2024
 
Videogame localization & technology_ how to enhance the power of translation.pdf
Videogame localization & technology_ how to enhance the power of translation.pdfVideogame localization & technology_ how to enhance the power of translation.pdf
Videogame localization & technology_ how to enhance the power of translation.pdf
 
Building AI-Driven Apps Using Semantic Kernel.pptx
Building AI-Driven Apps Using Semantic Kernel.pptxBuilding AI-Driven Apps Using Semantic Kernel.pptx
Building AI-Driven Apps Using Semantic Kernel.pptx
 
Building Your Own AI Instance (TBLC AI )
Building Your Own AI Instance (TBLC AI )Building Your Own AI Instance (TBLC AI )
Building Your Own AI Instance (TBLC AI )
 
UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6
 
Cybersecurity Workshop #1.pptx
Cybersecurity Workshop #1.pptxCybersecurity Workshop #1.pptx
Cybersecurity Workshop #1.pptx
 
UiPath Studio Web workshop series - Day 7
UiPath Studio Web workshop series - Day 7UiPath Studio Web workshop series - Day 7
UiPath Studio Web workshop series - Day 7
 
Computer 10: Lesson 10 - Online Crimes and Hazards
Computer 10: Lesson 10 - Online Crimes and HazardsComputer 10: Lesson 10 - Online Crimes and Hazards
Computer 10: Lesson 10 - Online Crimes and Hazards
 
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDEADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
 
Designing A Time bound resource download URL
Designing A Time bound resource download URLDesigning A Time bound resource download URL
Designing A Time bound resource download URL
 

Force

  • 1. + Force
  • 2. + FORCE  Force: is either a push or a pull that acts on an object.  Whenever you bend, twist, stretch or compress something you are using a pushing or pulling force.  Force is an effect which can,  Start motion,  Stop motion,  Change the speed or direction of motion,  Change the shape or size of a body.
  • 3. + Unit of Force  Force is represented by the symbol F and is measured in Newton (N).The pull of the Earth on a 100 g mass is about 1 N.
  • 4. + Measuring Force  The force is measured by a spring balance or dynamometer.
  • 5. + Action and Reaction  For every action force, there is always an equal but opposite reaction force. If an object applies a force on a second object, then the second object will exert an equal but opposite force on the first object.
  • 6. + TYPES OF FORCE  There are many different kinds of forces:  Gravitational force  Magnetic force  Electrostatic force  Tension  Frictional force
  • 7. + Gravitational Force and Weight  Gravitational Force: The force of attraction between two objects due to their masses  Gravitational force depends on;  The masses of the objects,  The distance between them.
  • 8. + Gravitational Force and Weight  Gravitational force is directly proportional to the product of the masses: The greater the masses the greater the gravitational force.  Gravitational force is inversely proportional to the distance between the masses: The larger the distance between the objects the smaller the gravitational force.  The pull of the earth on a 1 kg mass is about 10 N
  • 9. + Weight  Weight (w): The gravitational force acting on an object. Since it is a force it is measured by a spring scale and its unit is Newton (N).
  • 10. + How does weight change?  The weight of an object on the earth depends on its distance from the earth's centre.  Near the earth, an object of mass 1 kg has a weight of about 10 N, whereas 22 000 km away from the centre of the earth, the weight of the object reduces to 1 N.  The weight of an object of 1kg weighs most at the poles (9.83 N) and least at the equator (9.78 N). A body having a weight of 600 N at the equator would have a weight of 603 N at the poles
  • 11. + How does weight change?
  • 12. + How does weight change?  The weight of an object also changes from one planet to another since g is different for different planets. However the mass of the object is the same in all planets.
  • 13. + MASS WEIGHT It is the amount of matter It is the gravitational force contained in substance acting on an object It is the same everywhere It changes from place to place It is measured by equal arm It is measured by spring scale balance Its unit is kg Its unit is N It is a scalar quantity It is a vector quantity
  • 14. + MAGNETIC FORCE  Magnetic Force is the attractive or repulsive force between the poles of two magnets. Unlike poles attract each Like poles repel each other (a) other (b)
  • 15. + ELECTROSTATIC FORCE  Electrostatic Force is the attractive or repulsive force among electrically charged objects or electric charges such as electrons and protons.
  • 16. + TENSION  Tension (T): It is the pulling force in a rope or a chain.
  • 17. + FRICTIONAL FORCE  Frictional force: It is an important force which only acts when two objects are touching and are applying force to one another.  It is a force that slows down moving objects and brings them to rest.  It always acts in a direction opposite to the direction of the force applied to the object.  Walking is possible only on a frictional surface.  Water also applies a frictional force to the objects moving in it.  Frictional force does not depend on the area of the rubbing surfaces.
  • 18. +  The frictional force between the object and the table depends on two factors; a) The weight of the object. b) The roughness of the surfaces rubbing together.