Unit “I Can” Statements… Motion, Forces, & Energy Physical Science 7.1 Develop an understanding of chemical and physical interactions involving energy, & forces that affect motion of objects. f. Describe the effects of unbalanced forces on the speed or direction of an object’s motion. 1. variables that describe position, distance, displacement, speed & change in speed of an object) 2. gravity, friction, drag, lift electric forces & magnetic forces Unit “I Can” Statements… I can… Use SI units of mass & length appropriately; Define/calculate acceleration; Identify/describe forces and explain how they affect movement; Discuss unbalanced forces, their effect on movement, and how they cause acceleration; Calculate net force; Discuss balanced forces and how they affect movement; Explain Newton’s First Law… Discuss inertia; Explain how mass determines inertia; Explain Newton’s Second Law… Explain how acceleration & mass affect force; Calculate force Identify quantities related to force; Explain/demonstrate how changes in mass & force will change acceleration

What do you already know? Motion, Forces, & Energy What do you already know? Pre-Test Friction Second Law of Motion Acceleration Force Speed Inertia Velocity Weight Third Law of Motion Gravity Mass First Law of Motion image: http://divingaccessorysystems.com/ok-animated-question-marks/ http://homeschooling.about.com/library/newtonlawvocab.pdf

Motion, Forces, & Energy International System of Measurement (Metric System) A measurement system based on multiples of ten and on established measures of mass, length & time AKA – SI Based on the number 10 (makes for easier calculation) Image http://edtech2.boisestate.edu/hoeckp/502/imagemap.html

Motion, Forces, & Energy The International System of Measurement (SI) Scientists throughout the world use the SI system of measurement. Standard units are shown below. Measurement Definition SI Unit Symbol length the distance between two (2) points meter m volume (capacity) the measure of the amount of space an object occupies cubic meter m3 mass the measure of the amount of matter in an object gram g weight the measure of force Newton N temperature the measure of the amount of heat an object has degrees Celsius oC time the measure for the interval between two events second s area the measure of the number of square units needed to cover the faces or surfaces of a figure square meters m2

Motion, Forces, & Energy Using the Prefix Table Adding a prefix to a unit of measurement changes its value. Example… KILO + meter = 1,000 meters HECTO + meter = 100 meters DECI + meter = 0.1 meter CENTI + meter = 0.01 meter MILLI + meter = 0.001 meter

What SI unit of length would you use to describe the width/height of… Motion, Forces, & Energy What SI unit of length would you use to describe the width/height of… image http://deskarati.com/2011/03/05/tallest-buildings-in-the-world/ http://www.funbaz.com/wallpapers/birds/eagles/downloads/eagle-in-flight-750.jpg http://fc05.deviantart.net/fs71/i/2010/350/6/d/raindrop_by_nyffetyff-d3506p6.png http://www.planning.dot.gov/Documents/DomesticScan/images2/domscancover.gif

Motion, Forces, & Energy

Motion, Forces, & Energy What is the scientific definition of acceleration? In everyday language, acceleration means “the process of speeding up.” In science, acceleration is the rate in which velocity (speed in a given direction) changes. Three components… Increasing speed Decreasing speed Changing direction

Acceleration = Change in velocity Motion, Forces, & Energy Acceleration = Change in velocity Change in speed Change in direction Change in both

Motion, Forces, & Energy The batter accelerates the softball as she hits it. How does the motion of the ball change? The diver, skaters, and runners are all accelerating. Can you identify the change of motion in each example? Image: http://d24w6bsrhbeh9d.cloudfront.net/photo/a8WM7zV_700b.jpg http://www.taipei.gov.tw/public/MMO/TCGENG/75_34_01.jpg http://bloximages.newyork1.vip.townnews.com/enterprisepub.com/content/tncms/assets/v3/editorial/b/d2/bd2244f0-bda8-11e2-85e7-0019bb30f31a/519401f0a11af.preview-300.jpg

Motion, Forces, & Energy Components of Acceleration Increasing Speed Any time the speed of an object increases, the object experiences acceleration. The runners at the starting line accelerate as they increase their speed in the race. A gymnast accelerates as she runs into a tumbling routine. Other examples? Image: http://cdn.content.compendiumblog.com/uploads/user/3610b5d4-2339-4974-9fa2-6b400bf4f06c/042d5419-57ae-4ac3-ae89-987ca90c617c/Image/0787ecb2c7f09bf1267bd190b0135e3d.jpg

Motion, Forces, & Energy Components of Acceleration Decreasing Speed Motion in which speed DECREASES is also considered acceleration in science. (sometimes called deceleration or negative acceleration) The diver decelerates when traveling through the water. A aircraft lands on an aircraft carrier. Other examples? Image: https://www.acclaimimages.com/_gallery/_pages/0420-0904-2700-0334.html

Motion, Forces, & Energy Components of Acceleration Changing Direction Velocity involves both speed and direction An object can be accelerating even if its speed is constant. Skaters accelerate as they round the curve or change lanes The bikers accelerate as they make the curve. Other examples? Image: http://resources.edb.gov.hk/cphysics/mechanics/kin/acceleration/4-02.gif

Motion, Forces, & Energy Components of Acceleration Changing Direction Objects that continuously change direction without changing speed are accelerating. Objects moving in a circular motion are considered to be accelerating. Examples Ferris wheel Carousel Moon Earth Artificial Satellites Image: http://www.illustrationsof.com/1075355-royalty-free-ferris-wheel-clipart-illustration

Motion, Forces, & Energy Calculating Acceleration Acceleration describes the rate at which velocity changes. To determine the acceleration of an object, calculate the change in velocity during each unit of time.

Motion, Forces, & Energy Calculating Acceleration Velocity - measured in meters per second (m/s ) and Time - measured in seconds (s)… then Acceleration is meters per second per second (m/s2) Acceleration - change in velocity per unit of time Velocity - change in distance per unit of time Acceleration has two (2) units of time and therefore must be squared.

Calculating Acceleration Motion, Forces, & Energy Calculating Acceleration A roller coaster car rapidly picks up speed as it rolls down a slope. As it starts down the slope, its speed is 4 m/s. However, 3 seconds later, at the bottom of the slope, its speed is 22 m/s. What is its average acceleration. Step 1: Analyze the problem Step 2: Write the formula Step 3: Substitute & Solve Step 4: Think about it!

Calculating Acceleration Motion, Forces, & Energy Calculating Acceleration #1: Analyze the problem: Initial Velocity (IV) – 4 m/s Final Velocity (FV) – 22 m/s Time (T) – 3 seconds #2: Write the formula: #3: Substitute & Solve: #4: Think About It: The answer is reasonable. If the car’s velocity increases by 6 m/s each second, its velocity will be 10 m/s after one second, 16 m/s after two seconds, and 22 m/s after three seconds

Calculating Acceleration Motion, Forces, & Energy Calculating Acceleration Use the steps outlined in the last slide to help you solve these problems. A car advertisement states that a certain car can accelerate from rest to 90 km/h in 9 seconds. Find the car’s average acceleration. An eagle accelerates from 15 m/s to 22 m/s in 4 seconds. What is the eagle’s average acceleration? A train accelerates from 200 m/s to 500 m/s in 10 seconds. What is the train’s average acceleration?

Motion, Forces, & Energy Calculating Acceleration #1: Analyze the problem: Initial Velocity (IV) – _____ Final Velocity (FV) – _____ Time (T) – __________ #2: Write the formula: #3: Substitute & Solve: #4: Think About It: Is the answer reasonable? Why?

Motion, Forces, & Energy Part II Forces Newton’s Laws of Motion How do forces change all kinds of motion? Image: http://www.pushpullsigns.com/images/push-and-pull-sign-green-red.jpg

Motion, Forces, & Energy Make the Book Move… Move the book using different methods. What are some obvious ways to move the book? What are some creative ways to move the book? What was required to make the book move? Did the book move when there was no push or pull?

Motion, Forces, & Energy What Changes Motion? 1. Stack several metal washers on top of a toy car. 2. Place a heavy book on the floor near the car. 3. Predict what will happen to both the car & the washers if you roll the car into the book. Test your prediction. Observing: What happened to the car when it hit the book? What happened to the washers? What might be the reason for any difference between the motions of the car and the washers? Image: http://toolboxes.flexiblelearning.net.au/demosites/series10/10_01/content/bcgbc4010a/02_force_systems/03_newtons_first_law/page_001.htm

Motion, Forces, & Energy What type of motion is involved in these common activities? An arrow soaring through the air; A long jumper stops in a sand pit; A soccer ball is kicked around an opponent. Image http://theyeshiva.net/Article/View/150/My-Invisible-Emotions http://www.123rf.com/photo_5475779_male-long-jumper-landing-in-sand-pit.html http://users.rowan.edu/~martin4u/Kicking-Ball.gif

Motion, Forces, & Energy What type of motion is involved in these common activities? An arrow soaring through the air; (the force of the bow string on the arrow makes the arrow fly) A long jumper stops in a sand pit; (the force of the ground on the jumper makes the jumper stop) A soccer ball is kicked around an opponent. (the force of a toe on the ball makes the soccer ball change directions) Image http://theyeshiva.net/Article/View/150/My-Invisible-Emotions http://www.123rf.com/photo_5475779_male-long-jumper-landing-in-sand-pit.html http://users.rowan.edu/~martin4u/Kicking-Ball.gif

Motion, Forces, & Energy ?Question? So, why does each object move as it does? What causes the object to start moving? stop moving? change direction? Image http://theyeshiva.net/Article/View/150/My-Invisible-Emotions http://www.123rf.com/photo_5475779_male-long-jumper-landing-in-sand-pit.html http://users.rowan.edu/~martin4u/Kicking-Ball.gif

A FORCE is exerted (applied) to the object Motion, Forces, & Energy !Answer! A FORCE is exerted (applied) to the object Image http://theyeshiva.net/Article/View/150/My-Invisible-Emotions http://www.123rf.com/photo_5475779_male-long-jumper-landing-in-sand-pit.html http://users.rowan.edu/~martin4u/Kicking-Ball.gif

Simply stated, a push or a pull Motion, Forces, & Energy What is a force? Simply stated, a push or a pull When one object pushes or pulls another object, the first object is EXERTING a force on the second object Image: http://www.pushpullsigns.com/images/push-and-pull-sign-green-red.jpg

Applying a pressure that moves an object AWAY from the source. Motion, Forces, & Energy What is a push? Applying a pressure that moves an object AWAY from the source. Image: http://2.bp.blogspot.com/__laXXxBLiss/TC4Q-mBrUUI/AAAAAAAAAAY/-RvdQsPqFcI/s1600/push.gif

Applying a pressure that moves an object TOWARD the source. Motion, Forces, & Energy What is a pull? Applying a pressure that moves an object TOWARD the source. Image: http://bodybalance4you.files.wordpress.com/2013/01/31.gif

How are forces described? Motion, Forces, & Energy How are forces described? Just like velocity and acceleration, forces are described by their strength and direction. Image: http://www.pushpullsigns.com/images/push-and-pull-sign-green-red.jpg

Motion, Forces, & Energy Look at some common classroom items? How is the force that causes each of these objects to work applied? Hole puncher Stapler Printer paper tray Image: http://4.bp.blogspot.com/-rAwKW6Jcpvg/UMaFDeVyPoI/AAAAAAAAAVY/4waITYs9TU0/s1600/PUSH+PULL.jpg

Can you provide two examples of a push and pull? Motion, Forces, & Energy Can you provide two examples of a push and pull? Hole puncher Stapler Printer paper tray Image: http://4.bp.blogspot.com/-rAwKW6Jcpvg/UMaFDeVyPoI/AAAAAAAAAVY/4waITYs9TU0/s1600/PUSH+PULL.jpg

What do all these objects require to put them in motion? Motion, Forces, & Energy What do all these objects require to put them in motion? Hole puncher Stapler Printer paper tray A FORCE! Image: http://4.bp.blogspot.com/-rAwKW6Jcpvg/UMaFDeVyPoI/AAAAAAAAAVY/4waITYs9TU0/s1600/PUSH+PULL.jpg

Motion, Forces, & Energy ALL objects require either a push or pull to put them into motion, to stop them, or change their direction. Hole puncher Stapler Printer paper tray A FORCE! Image: http://4.bp.blogspot.com/-rAwKW6Jcpvg/UMaFDeVyPoI/AAAAAAAAAVY/4waITYs9TU0/s1600/PUSH+PULL.jpg

When two forces act in the same direction, they ADD together. Motion, Forces, & Energy Unbalanced Forces Mary needs to move this heavy box across the floor. If you help her, you and Mary will be exerting a force upon the box. The total force exerted on the box will be the sum of Mary’s force plus your force. When two forces act in the same direction, they ADD together. Hole puncher Stapler Printer paper tray Image: http://photos1.blogger.com/blogger2/232/4563/1600/lesson_3_heavy_box.jpg

Motion, Forces, & Energy Unbalanced Forces The head of each arrow shows the direction of the force. Unbalanced Forces The width of each arrow tell of the strength of the force.

Motion, Forces, & Energy Unbalanced Forces When forces act in opposite directions, they combine by subtraction (like positive and negative numbers).

Two forces may also cancel each other. Motion, Forces, & Energy Unbalanced Forces  Hole puncher Stapler Printer paper tray Two forces may also cancel each other. 

Motion, Forces, & Energy UNbalanced Forces Net Force Foldable NET Hole puncher Stapler Printer paper tray Force #1

Unbalanced Forces cause an object to Motion, Forces, & Energy UNbalanced Forces Net Force The overall force on an object when all the individual forces acting on an object are added together. Unbalanced Forces cause an object to Stop moving Start moving Change direction Hole puncher Stapler Printer paper tray

How do you calculate “net force”? Motion, Forces, & Energy Combined Forces How do you calculate “net force”? The force of the one push added to the force of the other pushes equals the net force. Force #1 Net Force Force #2

Motion, Forces, & Energy UNbalanced Forces Unbalanced forces acting on an object WILL CHANGE THE OBJECT’S MOTION – ONE WAY OR ANOTHER! In other words, unbalanced forces will cause an object to accelerate. Explain this in your own words. Hole puncher Stapler Printer paper tray

Motion, Forces, & Energy Combined Forces What is the net force acting on the car? (Unbalanced forces applied in the same direction) When two or more forces act in the same direction, the net force is the sum of the individual forces. The object moves in the direction of the “push”. Image: http://i.telegraph.co.uk/multimedia/archive/02256/pushing-car_2256323k.jpg

Unbalanced Force applied in the opposite direction… Motion, Forces, & Energy Combined Forces Unbalanced Force applied in the opposite direction… When forces act in opposite directions, the net force is the difference between the two forces. The object will move in the direction of the stronger force. Image: http://www.challenge.gov.sg/magazines/archive/2008_02/images/tug_of_war.jpg

Balanced forces moving in opposite directions… Motion, Forces, & Energy Combined Forces Balanced forces moving in opposite directions… When two or more equal forces act in opposite directions, they cancel each other out. The object doesn’t move. Image: http://3219a2.medialib.glogster.com/media/33/331fb979929fca639565d90f0694d77637411385e7ca5bbe0f1f1b062eced113/truck-balanced.gif

Motion, Forces, & Energy Balanced Forces Question… Will a force exerted (applied) to an object always change the object’s motion? Explain your answer! Hole puncher Stapler Printer paper tray Image: http://commons.wikimedia.org/wiki/File:Balance_justice.JPG

Motion, Forces, & Energy Balanced Forces Question… Will a force exerted (applied to) on an object always change the object’s motion? Explain your answer! Hole puncher Stapler Printer paper tray

Motion, Forces, & Energy Balanced Forces Look at the picture below. The dogs are pulling on the stocking in opposite directions. There are forces acting on the stocking, but the motion of the stocking does not change. Hole puncher Stapler Printer paper tray One dog exerts (applies) a force on the stocking in one direction, while the other dogs exert (apply) an equal force in the opposite direction.

one force equals the other force Motion, Forces, & Energy Balanced Forces Equal forces acting on one object in opposite directions – one force is balanced by the other force one force equals the other force Balanced forces acting on an object WILL NOT change the object’s motion. The net force of balanced forces in opposite directions is ZERO. – they cancel each other out! Hole puncher Stapler Printer paper tray

Newton’s Laws of Motion Motion, Forces, & Energy Newton’s Laws of Motion Hole puncher Stapler Printer paper tray

Motion, Forces, & Energy Newton’s First Law of Motion Galileo suggested some things about movement… He suggested that once an object is in motion, no push or pull is needed to keep it moving. Force is needed only to change the motion of an object. Whether moving or at rest, an object is going to resist change to its motion. Hole puncher Stapler Printer paper tray image http://www.esteri.it/NR/rdonlyres/A69A0C9C-C9DD-43B8-A7D4-6EA6998738AB/0/20090929_GalileoGalilei_dettaglio.jpg

Newton’s First Law of Motion Motion, Forces, & Energy Newton’s First Law of Motion Hole puncher Stapler Printer paper tray Image http://s563.photobucket.com/user/dorseydwa/media/INERTIA.png.html

Newton’s First Law of Motion Motion, Forces, & Energy Newton’s First Law of Motion Hole puncher Stapler Printer paper tray Image http://figures.boundless.com/50f8d142e4b0114e6c94a61e/full/seatbelt.png

Newton’s First Law of Motion Motion, Forces, & Energy Newton’s First Law of Motion Hole puncher Stapler Printer paper tray Image http://themotivationalposters.com/wp-content/uploads/2012/08/inertia-motivational-poster-2341.jpg

Motion, Forces, & Energy Newton’s First Law of Motion Hole puncher Stapler Printer paper tray How do all three of these images demonstrate inertia? Image http://s563.photobucket.com/user/dorseydwa/media/INERTIA.png.html http://figures.boundless.com/50f8d142e4b0114e6c94a61e/full/seatbelt.png http://themotivationalposters.com/wp-content/uploads/2012/08/inertia-motivational-poster-2341.jpg

Motion, Forces, & Energy Newton’s First Law of Motion Inertia The tendency of an object to resist change in its motion Hole puncher Stapler Printer paper tray In both, what does the object continue to do after the force is removed? Image http://www.toysgameus.com/images/listings/2013/06/06/air_hockey_tables_acclaim_4_5_foot_air_hockey_table.jpg http://www.popularmechanics.com/cm/popularmechanics/images/4J/free-throw-0312-de.jpg

Motion, Forces, & Energy First Law Newton’s First Law of Motion Galileo paved the way for Newton. An object at rest will remain at rest and An object in motion (at constant velocity) will continue moving (at constant velocity) until acted upon by an unbalanced force. Also called the LAW OF INERTIA First Law Hole puncher Stapler Printer paper tray

Motion, Forces, & Energy Newton’s First Law of Motion What explains the motion of these two objects? Hole puncher Stapler Printer paper tray image http://farm5.staticflickr.com/4010/4286671597_34656e8d32_z.jpg http://echnewt.wikispaces.com/file/view/rollercoster.jpg/199788206/rollercoster.jpg

Motion, Forces, & Energy Newton’s First Law of Motion Watch these videos about inertia. http://www.youtube.com/watch?v=u6rbrFgudLg http://www.youtube.com/watch?v=mn34mnnDnKU (through 3:39) http://www.youtube.com/watch?v=d7iYZPp2zYY Hole puncher Stapler Printer paper tray

Newton’s Laws of Motion Motion, Forces, & Energy Newton’s Laws of Motion Hole puncher Stapler Printer paper tray

Motion, Forces, & Energy Newton’s First Law of Motion Now, explain inertia to a 3rd grader. Use scientific terminology. Hole puncher Stapler Printer paper tray image http://farm4.static.flickr.com/3116/2583408414_8af54c8773.jpg http://garycombs.typepad.com/.a/6a00d83524c19a69e20120a95143c7970b-320wi

Motion, Forces, & Energy Newton’s First Law of Motion Inertia and the car crash… The “dummies” don’t stop when the car does. These “passengers” have inertia. What does that mean for them? Since they have inertia, what is needed to change their motion? What device is used to apply that force? What will apply that force if not for the seatbelt? Use science to convince a friend to use a SB! Hole puncher Stapler Printer paper tray image http://www.popsci.com/files/imagecache/article_image_large/articles/hiw-teaser-dummy.jpg

Motion, Forces, & Energy Newton’s First Law of Motion Mass Which is more difficult to move? Why? What’s the difference? They both occupy the same amount of space – so they have the same volume! The difference is the amount of mass each jar has. Mass – the amount of matter in an object Hole puncher Stapler Printer paper tray The jar of pennies has more mass than the jar of plastic peanuts – so the pennies would be more difficult to move! Image http://o.quizlet.com/i/iP8-q5QHuo5tqvNwJwLkGg_m.jpg

Motion, Forces, & Energy Newton’s First Law of Motion The SI unit of mass is the kilogram (kg). Hole puncher Stapler Printer paper tray Bicycle w/o a rider ~10 kg Small car ~1,000 kg Young Child ~45 kg Smaller objects can be described using the term grams. image http://www.autogaul.com/wp-content/uploads/2011/11/Small-Car-Skoda-Citigo-2013.jpg http://laredobuzz.com/wp-content/uploads/2011/05/bicycle.jpg http://cdn.sheknows.com/articles/2010/08/8-year-old-girl.jpg

Motion, Forces, & Energy Newton’s First Law of Motion Inertia depends upon its mass… The greater the mass of an object – the greater its inertia. Mass can be defined as a measure of the inertia of an object. Hole puncher Stapler Printer paper tray Image http://www.clker.com/cliparts/0/b/8/9/1216137609217389073Angelo_Gemmi_stone.svg.hi.png http://www.clker.com/cliparts/i/w/5/M/Y/x/cartoon-stone-th.png

95 Strategies for REMODELING INSTRUCTION, pg. 39 Motion, Forces, & Energy Newton’s First Law of Motion Graffiti Groups of no more than four. Take a turn writing something you know about Newton’s First Law. You may draw a picture or ask a question. After approximately 5 – 7 minutes, present your masterpiece to the class for discussion. Hole puncher Stapler Printer paper tray graffiti http://cooltext.com/Logo-Design-Graffiti-Creator-Button Strategy 95 Strategies for REMODELING INSTRUCTION, pg. 39

Newton’s First Law of Motion Motion, Forces, & Energy Newton’s First Law of Motion Use a double-bubble map to compare and contrast unbalanced and balanced forces. Explain Newton’s First Law to a younger student. Provide/illustrate and example. Building Vocabulary Skills _____ 3. inertia a. the amount of matter in an object _____ 4. mass b. sum of all forces acting on an object _____ 5. force c. tendency to resist a change in motion _____ 6. unbalanced forces d. push or pull _____ 7. balanced forces e. CAN change an object’s motion _____ 8. net force f. WILL NOT change an object’s motion Hole puncher Stapler Printer paper tray

Motion, Forces, & Energy Newton’s Second Law Read the article found at the URL below. We will answer some questions about this article later in the class. http://suite101.com/a/newtons-laws-for-kids-2nd-law-a41278

Motion, Forces, & Energy Newton’s Second Law When the adult pulls the wagon, it accelerates quickly. When one of the children pulls the wagon, the rate of acceleration is not nearly as fast. image http://www.step2.com/images/products/766500_offsitecommerce.jpg

Motion, Forces, & Energy Newton’s Second Law How is the acceleration of the wagon related to the force pulling it? How is the acceleration related to the mass of the wagon? image http://www.step2.com/images/products/766500_offsitecommerce.jpg

Motion, Forces, & Energy ??Question?? Newton’s Second Law If we dropped a marble and a wadded up piece of paper at the same time… Would they fall at an equal rate? What causes their acceleration as they fall? Which will hit with greater impact? Why? ??Question?? http://www.hometrainingtools.com/newton-s-laws-of-motion-science-projects/a/1256/

Motion, Forces, & Energy Newton’s Second Law This law explains how force, mass, and acceleration are related. The NET FORCE on an object is equal to the product of its acceleration & mass. F = (M)ass x (A)cceleration F = M x A

Motion, Forces, & Energy Net Force Foldable NET Force Force #2 Hole puncher Stapler Printer paper tray Force #1

What three (3) quantities are related in Newton’s Second Law? Motion, Forces, & Energy Newton’s Second Law What three (3) quantities are related in Newton’s Second Law?

Motion, Forces, & Energy Newton’s Second Law of Motion Watch these videos about force, mass, and acceleration. http://www.youtube.com/watch?v=mn34mnnDnKU (through 3:40 – 5:02) Hole puncher Stapler Printer paper tray

Motion, Forces, & Energy Newton’s Second Law !!!IMPORTANT!!! As with any equation, you must pay attention to the units of measurement. Mass kilograms (kg) Acceleration meters per second per second (m/s2) Force kilograms x meters per second per second kg * m/s2 A Newton

Motion, Forces, & Energy Newton’s Second Law A Newton Equals the force required to accelerate one kilogram of mass at one (1) meter per second per second 1N = 1kg x 1 m/s2 Named in honor of Isaac Newton image http://www.hdwallpaperspot.com/wp-content/uploads/2013/01/Sir-Isaac-Newton-Pictures.jpg

Motion, Forces, & Energy Newton’s Second Law A Newton If two of the three components are known, then the third can be calculated…

Motion, Forces, & Energy Newton’s Second Law A 52 kg water skier is being pulled by a speedboat. The net force causes her to accelerate at 2 m/s2. Calculate the net force that causes this acceleration. Step 3: Substitute & Solve… Force = M X A Force = 52 kg x 2 m/s2 Force = 104 kg x m/s2 Force = 104 kg  m/s2 Force = 104 N Step 1: Analyze – what do we know? Mass – 52 kg Acceleration – 2 m/s2 Step 2: Write the equation… Force = Mass X Acceleration Step 4: Think About It… Is this answer reasonable?

Motion, Forces, & Energy Newton’s Second Law Use the 4 step procedure illustrated on the previous slide to help you solve these problems… What is the net force on a 1,000 kg elevator accelerating at 2 m/s2? Step 3: Substitute & Solve… Step 1: Analyze – what do we know? Mass – __________ Acceleration – __________ Step 2: Write the equation… ______________________________ Step 4: Think About It… Is this answer reasonable?

Motion, Forces, & Energy Newton’s Second Law Use the 4 step procedure illustrated on the previous slide to help you solve these problems… What net force is needed to accelerate at 55 kg cart at 15 m/s2? Step 3: Substitute & Solve… Step 1: Analyze – what do we know? Mass – __________ Acceleration – __________ Step 2: Write the equation… ______________________________ Step 4: Think About It… Is this answer reasonable?

Motion, Forces, & Energy Newton’s Second Law Use the 4 step procedure illustrated on the previous slide to help you solve the problems… http://www.physicsclassroom.com/Class/newtlaws/U2L3a.cfm

Motion, Forces, & Energy Newton’s Second Law Changes in Force & Mass How can you increase acceleration of an object? How can you decrease acceleration of an object? What affect does the force exerted have on the acceleration? Images http://www.3m.co.uk/intl/uk/3mstreetwise/pupils-using-force.htm

Motion, Forces, & Energy Newton’s Second Law Changes in Force & Mass Acceleration and mass change in opposite ways... So, as net force increases, what happens to acceleration? Increased mass -- Decreased acceleration Decreased mass -- Increased acceleration Image http://dcpspublic.oncoursesystems.com/images/user/10290/584064/MassForceAcceleration.jpg

Let’s revisit this article below. Motion, Forces, & Energy Newton’s Second Law Let’s revisit this article below. http://suite101.com/a/newtons-laws-for-kids-2nd-law-a41278

Newton’s Laws of Motion Motion, Forces, & Energy Newton’s Laws of Motion Hole puncher Stapler Printer paper tray

Motion, Forces, & Energy Newton’s Second Law Changes in Force & Mass What is the acceleration of the wagon dependent upon? How could the man decrease the mass so that acceleration could increase? How could the man increase acceleration without changing the mass? How could we apply what we know about mass, force & acceleration to make the wagon accelerate as much as possible? image http://www.christart.com/IMAGES-art9ab/clipart/2366/pull-waggon.png

Motion, Forces, & Energy Newton’s Second Law Use the URL below to go to refresh your learning about Newton’s first two Laws of Motion. http://quizlet.com/1326638/chapter-11-force-newtons-laws-flash-cards/ On a sheet of paper (provided by Mrs. Carter), list five things you’ve learned about Newton’s Laws of Motion so far.