Newtons laws of_motion by gaurav,abeer,ayush and sumit

• 1. I. Law of InertiaII. II. F=maIII. Action-Reaction

2. physical principals discovered over 300 years ago by Sir Isaac Newton. Newtonworked in many areas of mathematics and physics. He developed the theoriesof gravitation in 1666, when he was only 23 years old. Some twenty years later, in1686, he presented his three laws of motion in the "Principia MathematicaPhilosophiae Naturalis." The laws are shown below, and the application of theselaws is given on separate slides. 3. Force is a push or a pull. It tends to changethe motion of an object. When you push a table, theforce makes the table move; consequently, the table isno longer in its state of rest.Effects of Force1. Force can stop a moving body.2. Force can move a stationary body.3. Force can change the speed or direction or both of amoving body.4. Force can change the shape and size of a body. 4. Isaac Newton used the results of Galileos experiment topropound the first law of motion. It is stated asfollows: A body at rest will remain at rest and a body inuniform motion will continue its uniform motionunless a unbalanced external force acts on it tochange its state of rest or uniform motion. 5. 1st Law of MotionThe motion of a rocket from the surface of the Earth to a landing onthe Moon can be explained and described by physical principalsdiscovered over 300 years ago by Sir Isaac Newton. 6. Inertia is thetendency of anobject to resistchanges in itsvelocity:whether inmotion ormotionless. These pumpkins will not move unless acted onby an unbalanced force. 7. Once airborne, unlessacted on by anunbalanced force(gravity and air fluidfriction), it wouldnever stop! 8. Unless actedupon by anunbalancedforce, this golfball would siton the teeforever. 9. Why then, do we observeevery day objects in motionslowing down and becomingmotionless seemingly withoutan outside force?Its a force we sometimes cannot see friction. 10. Objects on earth, unlike thefrictionless space the moontravels through, are under theinfluence of friction. 11. What is this unbalanced force that acts on an object in motion? There are four main types of friction: Sliding friction: ice skating Rolling friction: bowling Fluid friction (air or liquid): air or water resistance Static friction: initial friction when moving an object 12. Slide a book across a tableand watch it slide to a restposition. The book comes to arest because of the presence ofa force - that force being theforce of friction - which bringsthe book to a rest position.In the absence of a force offriction, the book wouldcontinue in motion with thesame speed and direction -forever! (Or at least to the endof the table top.) 13. In the absence of a force of friction, the book wouldcontinue in motion with the same speed and direction- forever! (Or at least to the end of the table top.) 14. Dont let this be you. Wear seat belts.Because of inertia, objects (including you) resist changesin their motion. When the car going 80 km/hour is stoppedby the brick wall, your body keeps moving at 80 m/hour. 15. The net force of an object is equal to theproduct of its mass and acceleration, or F=ma. When mass is in kilograms and acceleration is inm/s/s, the unit of force is in Newton (N). One Newton is equal to the force required toaccelerate one kilogram of mass at onemeter/second/second. 16. Newtons 2nd Law proves that different massesaccelerate to the earth at the same rate, but withdifferent forces. We know that objectswith different massesaccelerate to theground at the samerate. However, because ofthe 2nd Law we knowthat they dont hit theground with the sameforce.F = ma98 N = 10 kg x 9.8 m/s/sF = ma9.8 N = 1 kg x 9.8 m/s/s 17. For every action, there is anequal and opposite reaction. 18. According to Newton,whenever objects Aand B interact witheach other, they exertforces upon each other.When you sit in yourchair, your body exertsa downward force onthe chair and the chairexerts an upward forceon your body. 19. There are two forcesresulting from thisinteraction - a force onthe chair and a force onyour body. These twoforces are called actionand reaction forces. 20. Consider the propulsion of afish through the water. A fishuses its fins to push waterbackwards. In turn, the waterreacts by pushing the fishforwards, propelling the fishthrough the water. The size of the force on thewater equals the size of theforce on the fish; thedirection of the force on thewater (backwards) is oppositethe direction of the force onthe fish (forwards). 21. Flying gracefullythrough the air, birdsdepend on Newtonsthird law of motion. Asthe birds push down onthe air with their wings,the air pushes theirwings up and givesthem lift. 22. The reaction of a rocket isan application of the thirdlaw of motion. Variousfuels are burned in theengine, producing hotgases.The hot gases push againstthe inside tube of the rocketand escape out the bottomof the tube. As the gasesmove downward, the rocketmoves in the oppositedirection.