Warm-Up Introduction To Forces - PitteScience

Warm-Up?Introduction to ForcesLessonQuestionHow do forces affect the motion of an object?Lesson GoalsDistinguishExplain how tobetween balanceddetermine the netand unbalancedforce on anforces and theirDescribe theconcept offorce.object.effects onmotionW2K.Words to KnowWrite the letter of the definition next to the matching word as you work through thelesson. You may use the glossary to help you.B magnitudeC forceA frictionF gravityD normal forceE vector Edgenuity, Inc.A. a resistance to motion caused by twosurfaces rubbing against each otherB. the size or quantity of somethingC. a push or pullD. the support force a surface exerts on anobject; always at a ninety-degree angle to thesurfacea push or pullE. a quantity that has both a size and a directionF. the force that one massive object exerts toattract another object to it; expressed as theweight of an object1

Warm-UpIntroduction to ForcesMotion Motion is recognized when an object’spositionfrom a referencepoint changes. Motion can be described by: aspeed avelocity an Edgenuity, Inc.acceleration.2

InstructionIntroduction to ForcesSlide2Forces Aforce Forces areis a push or avectorspull. A vector has both a magnitude and a MagnitudedirectionMagnitudeis the size or quantity of something. A vector is indicated with anarrow A vector can have a positive or Forces are measured in4.newtons.negativevalue.(N).Force Diagrams and Abbreviations A force diagram is a drawing with forcevectorswhose sizes anddirections represent the magnitudes and directions of the forces acting onan object. Abbreviations are used to identify which type of force eachvector represents. Thelengthof a force vector represents the magnitude, or size,of the force. Thedirectionof the force vector shows which direction the forceis acting in and abbreviations to tell you what type of force eachvector represents. Edgenuity, Inc.3

InstructionIntroduction to ForcesSlide4Force Diagrams and Abbreviations Some common forces are: Push or pull,Normal a90 Friction, 7Fpforce, FN: always at-degree right angleFfGravity: slows object down, Fg: weightWords to Knowto act against something, causing it to havecounteractlessof an effectnet forcethesumof all of the forces acting on an objectMultiple Forces Forces that act in the same direction Forces that act in opposite directions Edgenuity, Inc.combine.counteracteach other.4

InstructionIntroduction to ForcesSlide7Net Force The net force is the sum of all of theforcesthat act on an object.direction Positive and negatives have to be assigned forbefore adding forces together. When assigning positives and negatives to forces, forces pointing totherightare positive, and forces pointing to theleftare negative.Label the forces shown as positive ( ) or negative (–).— The net force in the illustration is Edgenuity, Inc. —25 N.5

InstructionIntroduction to ForcesSlide7Parallel Forces Onlyparallel Left and Up andforces can be added together.rightdowncan be added together.can be added together.Label the forces shown as positive ( ) or negative (–). — The sum of the forces acting on this piano is Edgenuity, Inc.500 N.6

InstructionIntroduction to ForcesSlide10Balanced Forces When forces acting inoppositezero The net force is There is no change indirections are exactly equal:.motion. It’s important to know that a zero net force doesnotmean thereis no motion. It simply means that there is no change from what isalready happening.Unbalanced Forces When forces acting in opposite directions areunequal: The net force is positive or negative in the direction of thegreaterforce. There is a change in motion.SpeedDirection Both speed and direction The motion of the object is in the samedirectionas the netforce. Unbalanced forces can start an object moving or stop an object from moving. Edgenuity, Inc.7

InstructionIntroduction to ForcesSlide12Force Diagrams and Unbalanced Forces Force diagrams show when forces are balanced or The length of the vector represents the The longer the vector is themoreunbalancedstrength.of the force.force there is. The net force and the motion will be in the direction of thelongestvector.Circle the vector that represents the largest force. Edgenuity, Inc.8

Summary?Introduction to ForcesLessonQuestionHow do forces affect the motion of an object?Answer(Sample answer) Unbalanced forces acting on an object canchange the object’s speed, direction, or both. Balanced forces donot affect the motion of an object.Slide2Review: Key ConceptsFORCESforce A Forces areis a push or a pull.vectorswith magnitude and direction. Force diagrams show the type, magnitude, anddirectionof the forcesacting on an object. Edgenuity, Inc. Push Gravity, Fg Normal, FN Friction, Ffor pull, Fp9

SummaryIntroduction to ForcesSlide2Review: Key ConceptsNET FORCE Thenetforce is the sum of all forces acting on an object. A net force of zero means that all forces are inbalanceand there is no change in motion. A positive or negative net force causes a change in motion in thedirection of thegreaterforce.Use this space to write any questions or thoughts about this lesson. Edgenuity, Inc.10

Introduction to Forces? How do forces affect the motion of an object? Describe the concept of . Distinguish between balanced and unbalanced forces and their effects on . Explain how to determine the net force on an. force object motion Words to Know Write the letter of the definition