1 / 51

Kinematics FORCE

Kinematics FORCE. AND. By: Mrs. Shazia Pervaiz DA Neelum High School. MOTION. KINEMATICS:. Kinematics is the branch of classical mechanics that describes the motion of bodies (objects) and systems (groups of objects) without consideration of the forces that cause the motion.

trygg
Download Presentation

Kinematics FORCE

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Kinematics FORCE AND By: Mrs. Shazia Pervaiz DA Neelum High School MOTION

  2. KINEMATICS: Kinematics is the branch of classical mechanics that describes the motion of bodies (objects) and systems (groups of objects) without consideration of the forces that cause the motion. The four kinematic equations that describe an object's motion are:

  3. Kinematics involves position, velocity and acceleration (and their rotational equivalents). •Position is the point in space that an object occupies. •Velocity is the rate of change of position with respect to time. •Acceleration is the rate of change of velocity with respect to time.

  4. REST A body is said to be at rest if it does not change its position with respect to surrounding.

  5. Motion A body is said to be in motion if it keeps on changing its position with respect to its surrounding.

  6. Displacement It is the shortest directed distance between two points. It is a vector quantity. It is measured by a straight line that is linear distance, and in a specific direction both magnitude and direction are important. Displacement

  7. Velocity Velocity is defined as the rate of change of displacement. It is speed in a specified direction. When you are asked for the velocity of an object, you have to state the speed of the object and the direction in which it is travelling. Velocity= Displacement / Time taken

  8. Acceleration Acceleration is defined as the rate of change of velocity. The direction of the acceleration is the direction of change of velocity. The SI Unit for acceleration is meter/sec/sec (m/s2) Acceleration= Change in velocity/ Time taken

  9. GRAVITY: “Force of attraction between all objects in the universe.” Gravitational Forces Newton eventually came to the conclusion that, in fact, the apple and the moon were influenced by the same force. He named that force gravitation (or gravity) after the Latin word gravitas which literally translates into "heaviness" or "weight.“ In the Principia, Newton defined the force of gravity in the following way (translated from the Latin): “Every particle of matter in the universe attracts every other particle with a force that is directly proportional to the product of the masses of the particles and inversely proportional to the square of the distance between them.”

  10. The Earth is a very large object and it is also very heavy. This means that it has got a strong gravitational field.The moon is smaller than the Earth and is not as heavy.

  11. Acceleration due to Gravity: All bodies fall to the ground with the same acceleration irrespective of their masses. This acceleration is due to the attraction of earth hence it is known as acceleration due to gravity. The value of acceleration is 9.8 m/s2. Compare the equation of bodies freely falling on the ground with the equation of bodies moving on the ground.

  12. FORCES Forces are pushes or pulls (a combination is a twist).   Objects are stationary when forces are balanced gravity is always acting but we don’t keep falling due to a support force Forces can be measured using a Newton meter.

  13. FORCE PAIRS Forces act in pairs (e.g. thrust and friction, gravity and support). Force diagrams show the forces acting on an object and whether they are balanced or unbalanced. Arrow size represents force size if no measurements are available.

  14. Bloom Based Objectives Topic 1: Motion and laws of motion Level: 10th Learning Objectives At the end of the lesson students will be able to: Distinguish first and second law of motion and make an out line. (Analysis) Rate laws of motion according to use in daily life and do experiment.(Evaluation) Compose a story for Newton’s laws. (Creation) h

  15. Title: Motion Description: This session will allow students to understand that ideas that Newton came up with in order to explain movement. Grade Level: 10thCurriculum: Science Keywords: Motion, inertia, force, acceleration, mass and weight

  16. First Law Of Motion “In the absence of a net force , a body at rest will remain at rest and a body in motion will continue its motion until a force is applied”

  17. Second Law Of Motion When an external force acts on a body it will accelerate in the direction of the force . The magnitude of the force is directly proportional to the produced acceleration F = ma

  18. Third Law Of Motion To every action there is always equal and opposite reaction

  19. Work Sheet For you to successfully understand this session attempt to do the following:Identify how each law can be applied to your everyday life. Explain the equation F=ma.Define the key terms: acceleration, force, inertia, mass and weight

  20. Evaluation In groups answer these questions and present them in a PowerPoint or video presentation: In your own words, give the definition of the key terms. Explain Newton's first, second and third law and provide an example for each.

  21. Creation Roller coasters are examples of the laws of physics in operation. Roller coasters are pulled to the top of the highest hill, then released. Gravity and friction control the rest of the ride. Why don’t the cars of a roller coaster fly off the track? Why don’t the passengers fly out of the cars? How high can the first hill of a roller coaster be? What physical laws determine how many hills, curves, and loops a roller coaster track can have?

  22. Task Your job is to find out how roller coasters work and use this information to design a simple model of a roller coaster. You will learn about roller coaster design, laws of motion, and about velocity and acceleration. You will write a report describing your design of a rollercoaster. Then, you will design that roller coaster virtually and see what happens to the roller coaster when you change variables such as height of hills, length of track, mass of the coaster, and speed of the coaster. 

  23. Bloom Based Objectives Topic 2 : Friction Learning Objectives At the end of the lesson students will be able to: Categorize types of friction and make a flow chart. (Analysis) Tell why rolling friction is less than sliding friction and do an experiment. (Evaluation) Make a project to reduce friction. (Creation)

  24. Friction When two bodies slides over the surface of another body , an opposing force is set up to resist the motion , The force which opposes the motion is called friction, it causes heat, damage, wear and slowing  Friction can be reduced by… lubrication, streamlining (aerodynamics), slowing down, smoothing surfaces

  25. What causes friction? There are two factors which affect friction between two surfaces: • Kind of surfaces in contact (rough or smooth) • Amount of force pressing the surfaces together. • The rougher the surface and the stronger the force between the surfaces, the greater the amount of friction. • Coefficient of friction • It is the ratio between force of friction and perpendicular reaction • µ = F/R

  26. From Glencoe Physical Science Types of Friction Static friction: If you were trying to move a box like pictured below and the box did not move, this would be static friction. Static friction is friction between two surfaces which are not moving on each other.

  27. Glencoe Physical Science Types of Friction • What is rolling friction? • Rolling friction is the friction which enables wheels to turn and objects to move. If there were no friction, turning wheels would not enable an object to move. Sliding friction: Sliding friction occurs when a force is great enough to overcome the static friction.

  28. Limiting Friction: The maximum force of the friction which just stops the body from moving is called limiting friction

  29. Factors on which Limiting Friction Depends Experiments show that the limiting friction depends on two factors: Normal reaction R Nature of the surfaces in contact. Fs ∞ R Fs= µR µ= Fs/ R

  30. Types of Friction Air Resistance – another type of friction : Air resistance is a force which opposes a moving object. This can be easily seen with falling objects. When a piece of paper and a crumple piece of the same type of paper are dropped, they fall at the same rate. A coin and a feather dropped in air will not fall at the same rate, but a coin and feather dropped in a vacuum (no air) will fall in same rate.

  31. Advantages It helps to move forward Nut and bolt can hold a body due to friction A nail stays in the wood because of friction We can not hold anything without friction We can tie a knot because of friction

  32. Disadvantages In a car oil under pressure is supplied continuously to ball bearing surface. Failure of the oil supply will allow metal to metal contact and resulting friction , often raises the temperature and due to this ball bearing and piston are sized up. Due to friction the efficiency of machine is less than 100% Due to friction machines catches fire.

  33. Methods to reduce friction The various parts of the machine which are moving over one another are properly lubricated. In machines the sliding of various parts are usually replaced by rolling and this is done by using ball bearings. Where is sliding is unavoidable a thick layer of greasing material is used between the sliding surfaces. The front of the fast moving object made oblong to minimize friction.

  34. Bloom Based Objectives Topic: Momentum and law of conservation of momentum Learning Objectives At the end of the lesson students will be able to: Compare momentum and motion and write a report. (Analysis) Evaluate value of momentum when mass and velocity are given and write conclusion. (Evaluation) Generate a game to explain law of conservation of momentum. (Creation)

  35. Momentum Quantity of motion of a body is referred to as "MOMENTUM".    Momentum of a moving body defined as : "the product of mass and velocity of a body is called MOMENTUM."    Mathematically Momentum = mass x velocity    It is a vector quantity. Momentum is always directed in the direction of velocity.   The unit of momentum is in S.I system kg .m/s    Momentum depends upon mass and velocity of body.

  36. Law Of Conservation of Momentum “When some bodies constituting an isolated system act upon one another, the total momentum of the system remains constant." OR “The total momentum of an isolated system of interacting bodies remains constant."OR"Total momentum of an isolated system before collision is always equal to total momentum after collision."    Consider an isolated system of two bodies 'A' and 'B' as shown. The masses of bodies are ma and mb

  37. MATHEMATICAL REPRESENTATION  Consider two bodies of mass m1 and m2 moving initially with velocities u1 and u2.  Total momentum before collision = m1u1 + m2u2  Let after collision their velocities become v1 and v2.  Total momentum after collision = m1v1 + m2v2    According to the law of conservation of momentum m1u1 + m2u2 = m1v1 + m2v2

  38. ACTION PLAN FORCE AND MOTION CLASS: 10TH By: Mrs .Shazia Pervaiz DA Neelum High School

  39. Long Term Goal Using 21st century approaches it will be tried to develop 21st century skills specially creativity and critical thinking. Mrs.Shazia Pervaiz

  40. Short Term Goals To encourage student in creating and thinking new ideas. To aware student about use of technology To generate curiosity among student Mrs.Shazia Pervaiz

  41. Bloom Based Objectives Topic1: Motion and laws of motion Level: 10th Learning Objectives At the end of the lesson students will be able to: Distinguish first and second law of motion and make an out line. (Analysis) Rate laws of motion according to use in daily life and do experiment.(Evaluation) Compose a story for Newton’s laws. (Creation)

  42. Topic 2: Friction Learning Objectives At the end of the lesson students will be able to: Categorize types of friction and make a flow chart. (Analysis) Tell why rolling friction is less than sliding friction and do an experiment. (Evaluation) Make a project to reduce friction. (Creation)

  43. Topic 3: Momentum Learning Objectives At the end of the lesson students will be able to: Compare momentum and motion and write a report. (Analysis) Evaluate value of momentum when mass and velocity are given and write conclusion. (Evaluation) Generate a game to explain law of conservation of momentum. (Creation)

  44. Instructional strategies Mrs.Shazia Pervaiz

  45. =

  46. Time Line Mid Term Mrs.Shazia Pervaiz

  47. Challenges and solutions Challenges • Student motivation • Management • Game • Story • Unwillingness of std. • Apparatus for practical(Evaluation) • Use of computer lab • Solutions • Use of net searching • Group discussion • Net Searching • Net Searching • Activity based teaching • Science lab • Arrangement of periods Mrs.Shazia Pervaiz

  48. Resources Sind text book of physics CO-ordinated science Physics by Stephen Pople www.google.com www.answers.com www.youtube.com www.wikipedia.com

More Related