Presentation on theme: "Ship the Chip Sort It Out Pulleys and Force"— Presentation transcript:
1Ship the Chip Sort It Out Pulleys and Force TISP: Uruguay 9–10 May 2009User Handout Day 1Ship the Chip Sort It Out Pulleys and ForceChristopher LesterYvonne PelhamMoshe KamD.G. Gorham
2Package design and the engineering behind shipping products safely Exercise 1:Ship The ChipPackage design and the engineering behind shipping products safely
3Ship the ChipThe ChallengeDesign a package that will securely hold a potato chip and protect it from breaking when droppedConstruct the lightest package to get the highest scoreOverall score based on:Weight of the packageVolume of the packageIntactness Score
4Ship the Chip Procedure Sketch a design on the worksheet Label your worksheet with Table # and Team NameConstruct a model of your packageAt a test station, drop the package from a height of 1.5 metersOpen your package and examine the chipCalculate and record your scoreUsing a second kit, redesign and construct a new packageRecord the second design on the worksheetLabel your package with Table # and Team NameSubmit your worksheet and package to the Test Team for overnight testing
5Ship the Chip Materials Cardboard – 22 cm x 28 cm 10 Craft sticks 6 Cotton BallsString – 91 cmPlastic wrap – 1 sheet of 22 cm x 28 cm10 ToothpicksFoil – 1 sheet of 22 cm x 28 cmPaper – 1 sheet of 22 cm x 28 cm1 Mailing label1 Potato Chip
6Ship the Chip Tools and Accessories Scissors Marking pen Pencils/Pens CalculatorRulersClear Adhesive TapeDigital ScaleMasking Tape
7Ship the Chip Scoring Intactness score : 100: like new, perfect 50 : slightly damaged; cracked but still in one piece25 : broken in pieces5 : broken in 6-20 pieces1 : broken into more than 20 pieces; crumbled
8Ship the Chip Calculating Volume We will imbed the package in the smallest-volume rectangular prism that contains itWe will calculate the volume of the prism;Width x Length x HeightFor example : 3cm x 4cm x12cm =144 cm3 in the prism shown belowIf your package weighed 100g and had a volume of 800 cm3 and the chip has arrived broken in 3 pieces:
10Sort It Out Your Turn Groups of 2 You are a team of engineers hired by a bank to develop a machine to sort coins that are brought in by customers.Must mechanically sort mixed coins into separate containers.In our experiment we use washers:½ Inch1 Inch1¼ Inch1½ Inch
11Distance from correct bin here, Derror = 2 bins Sort It OutYour TurnHow good is it?1: “Distance” performance index:A washer that does not get sorted has maximum Derror = 3½in1in1¼in1½in11¼1½11¼11¼1½111¼1¼11½11½Distance from correct bin here, Derror = 2 bins
12Sort It Out Your Turn 5% How good is it? 2: “Percentage” performance index:½in1in1¼in1½in11¼11½11¼1¼1½111¼1¼11½11½# of washers incorrectly identifiedTotal # of washers to sort405%
13Sort It OutYour TurnDesign (draw) a mechanical sorter that can separate the ½in, 1in, 1¼in, 1½in washersInput: eitherParallel – all washers are inserted at start of your sorter together; orSerial – washers are inserted at start of your sorter one at a timeOutput: Each size of washer in its own physical containerMaterials:glue, tape, paper or plastic plates, cardboard, scissors or hole punch, foil, paper, cardboard tubeswashers
14Sort It OutYour TurnAt your table, choose 2 groups to build a parallel sorter; the other 2 groups will build a serial sorterYou will have 45 seconds to allow your sorter to operatePredict the value of the two performance indices for your designConstruct your sorting mechanismTest it!Can you do better?
15All about force and how pulleys can help reduce it Exercise 3:Pulleys & ForceAll about force and how pulleys can help reduce it
16Pulleys & Force Basics of Pulleys: Two orientations Fixed Pulley Movable Pulley
17Pulleys & Force Mechanical Advantage Mechanical Advantage (MA) is the factor by which a mechanism multiplies the force or torque put into it.Ideal MA:Actual MA:This movable pulley system has a mechanical advantage of 2
18Pulleys & ForceWorkWork is the amount of energy transferred by a force acting through a distanceWork = Force x Distance Work = Force x DistanceA bigger mechanical advantage decreases the force required, but increases the distance over which it must be appliedThe total amount of work required to move the load stays the same
19Pulleys & Force Efficiency The ratio between Actual and Ideal mechanical advantage is EfficiencyFrictionless system = 100% Efficiency
20Pulleys & Force Measuring Tension Spring Scale Calibrate: Hold spring scale at eye-level and turn adjustment screw until the internal indicator is precisely aligned with the top zero lineMeasure: Create a loop in the end of the rope you want to measure tension in; attach spring scale to loop. Hold the spring scale steady and read off the tension measurement.
21Pulleys & Force Your Turn Groups of 2 Develop 2 systems to lift a filled soda bottle 10cm with1 pulley2 pulleysBuild your systemsMeasure the distance the soda bottle moves and compare it to the distance you had to pullWhat is the actual mechanical advantage?Measure the force you must exert on the string and compare it to the force that is finally transmitted to the soda bottleWhat is the ideal mechanical advantage?Calculate the efficiency of each system
22Pulleys & Force Your Turn Now join with one other group at your table Develop 2 different systems to lift a filled soda bottle 10cm with all 4 pulleysBuild both systemsWhat are their actual mechanical advantages? Ideal?Which one has a better efficiency? Why do think that is?