FORCE & MOTION Instructional Module 6 Dr. Alok K. Verma Lean - PowerPoint PPT Presentation

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences FORCE & MOTION Instructional Module 6 Dr. Alok K. Verma Lean Institute - ODU 1

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Description of Module • Study of different types of forces like Friction force, Weight force, Tension force and Gravity. • This Module studies relationship between forces and the different types of Motion they produce, using Newton’s three laws of Motion. Dr. Alok K. Verma Lean Institute - ODU 2

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Targeted Sols : A-1, 3, 11, 15,G -3, 4, 9 , AII-2,3 ,T-3, AII/T-3, AII/T-2 PH - 5d , 5C , 5E Learning objectives Activity Identify the forces that cause an object’s Force and motion motion Tension Calculate tension on string and force acting on it. Hooke's law To verify Hooke's law relation ship between force and elongation Projectile motion How projectile angle effects range and velocity on different masses. Gravity Calculate weight on different planets Acceleration Calculate acceleration on connected objects Dr. Alok K. Verma Lean Institute - ODU 3

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Topics Covered No Topic Time 1. Force and Motion 2. Balanced and Unbalanced forces 3. Types of Forces 4. Types of Friction. 5. Tension Force Hooke’s law 6. 7. Gravity 8. Mass and Weight 9. Newton's First Law 10. Newton's Second Law 11. Newton's Third Law Dr. Alok K. Verma Lean Institute - ODU 4

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Force &Motion Force: A push or pull that one body exerts on another. Motion: A Change of Position or Location. Dr. Alok K. Verma Lean Institute - ODU 5

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Unit of Force • Forces are measured in Newton • A Newton is the force required to give a mass of 1 kilogram ( 1 kg ) an acceleration of 1 meter per second per second ( 1 m/s 2 ). It is abbreviated as N . • 1 N is equivalent to 1 kg-m/s 2 . Dr. Alok K. Verma Lean Institute - ODU 6

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Different Ways of Measuring Force 1. Spring Scale 2. Force Meter 3. Force Gauges a) Mechanical Gauges b) Digital Gauges 4. Dynamometer Dr. Alok K. Verma Lean Institute - ODU 7

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Balanced Forces • Balanced forces do not cause change in motion • They are equal in size and opposite in direction F F F F Dr. Alok K. Verma Lean Institute - ODU 8

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Unbalanced Forces • An unbalanced force always causes a change in motion • They are not equal in size and opposite in direction F F 2F 2F Dr. Alok K. Verma Lean Institute - ODU 9

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Which one is balanced and unbalanced? 4 N, left – 4 N, right 4 N, left – 10 N, right Dr. Alok K. Verma Lean Institute - ODU 10

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Answers Which one is balanced and unbalanced? 4 N, left – 4 N, right 4 N, left – 10 N, right Balanced Unbalanced Dr. Alok K. Verma Lean Institute - ODU 11

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Types of Forces 1. Normal force 2. Friction Force 3. Tension force 4. Gravitational Force 5. Spring Force 6. Electromagnetic Force 7. Nuclear force Dr. Alok K. Verma Lean Institute - ODU 12

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Normal Force It is the force exerted by one surface on another. It is perpendicular to the surface. Normal Force (F n ) Friction Force (F f ) Weight of block (W) Dr. Alok K. Verma Lean Institute - ODU 13

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences The person is walking on the floor and he slips suddenly. What is the reason? Because of lack of Friction Dr. Alok K. Verma Lean Institute - ODU 14

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Friction Force Force that opposes motion between two surfaces. Depends on the: • types of surfaces • different materials Normal force (F n ) F f = m F n Friction force (F f ) Coefficient of friction Dr. Alok K. Verma Lean Institute - ODU 15

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Four Types of Friction 1. Static Friction : Force that acts on objects that are not moving Dr. Alok K. Verma Lean Institute - ODU 16

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Four Types of Friction 2. Sliding Friction : Force resulting when pushing or pulling an object over a surface Dr. Alok K. Verma Lean Institute - ODU 17

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Four Types of Friction 3. Rolling Friction : is the resistance that occurs when a round object such as a ball or tire rolls on a flat surface. Much easier to move object. Dr. Alok K. Verma Lean Institute - ODU 18

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Four Types of Friction 4. Fluid Friction : Solid moving through a liquid or a gas • Force of a fluid friction is always less than sliding friction • The resistance that a body experiences in fluid is knows as Drag force. This is proportional to square of velocity of a body. Dr. Alok K. Verma Lean Institute - ODU 19

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Coefficient of Friction Coefficient of Friction ( µ ) (mu): It is the ratio of the force of friction between two bodies and the force pressing them together. We use the symbol µ (Greek alphabet). Value of µ depends on the two surfaces involved and material they are made up of. Example : Teflon on steel has a low coefficient of friction. µ = 0.04 Rubber on concrete has a high coefficient of friction. µ = 1.0 Dr. Alok K. Verma Lean Institute - ODU 20

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Calculation of Coefficient of Friction Coefficient of Friction ( µ ) can be calculated experimentally by the following formula: Normal Force (F n ) Friction Force (F f ) µ = Height/ Length Height Length Weight of block (W) Dr. Alok K. Verma Lean Institute - ODU 21

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences 1. The direction of friction is always ________ to the direction in which the object is moving . a. Same b. Opposite c. Unrelated 2. When an object is moving faster through a fluid – what happens to the force of friction on it? a. Force of Friction increases. b. Force of Friction decreases . c. There is no force. Dr. Alok K. Verma Lean Institute - ODU 22

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Answers 1. The direction of friction is always ________ to the direction in which the object is moving . a. Same b. Opposite c. Unrelated 2. When an object is moving faster through a fluid – what happens to the Drag force? a. Drag Force increases. b. Drag Force decreases . c. There is no force. Dr. Alok K. Verma Lean Institute - ODU 23

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Hands on Activity - 1 Measure Coefficient of Friction Dr. Alok K. Verma Lean Institute - ODU 24

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Hands on Activity - 1 Measure Coefficient of Friction Objective: Measuring the coefficient of friction between different surfaces. Materials for class activity: 1. A Flat corrugated plastic board to be used as a ramp. 2. Square block with six different surfaces.(Copper,Brass,Rubber, Wood(Rough surface),Wood(Smooth Surface),Cork sheet. 3. 12” Ruler. 4. 3 dowels. 5. Base Stand. 6. Square beam with pulley. 7. Wooden clamp Dr. Alok K. Verma Lean Institute - ODU 25

MarineTech 2009 - 2011 STEM Preparation through Marine Engineering, Science and Technology Experiences Assembled Equipment : Dr. Alok K. Verma Lean Institute - ODU 26