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Ship the ChipSort It OutPulleys and Force

Christopher Lester

Yvonne PelhamMoshe Kam

D.G. Gorham

TISP: Uruguay

9–10 May 2009

User Handout Day 1

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Package design and the engineering behind shipping products safely

Exercise 1:

Ship The Chip

3+Ship the Chip

Design a package that will securely hold a potato chip and protect it from breaking when dropped

Construct the lightest package to get the highest score Overall score based on:

Weight of the package Volume of the package Intactness Score

The Challenge

4+Ship the Chip

1. Sketch a design on the worksheet Label your worksheet with Table # and Team Name

2. Construct a model of your package

3. At a test station, drop the package from a height of 1.5 meters

4. Open your package and examine the chip

5. Calculate and record your score

6. Using a second kit, redesign and construct a new package Record the second design on the worksheet

7. Label your package with Table # and Team Name

8. Submit your worksheet and package to the Test Team for overnight testing

Procedure

5+Ship the Chip

Cardboard – 22 cm x 28 cm 10 Craft sticks 6 Cotton Balls String – 91 cm Plastic wrap – 1 sheet of 22 cm x 28 cm 10 Toothpicks Foil – 1 sheet of 22 cm x 28 cm Paper – 1 sheet of 22 cm x 28 cm 1 Mailing label 1 Potato Chip

Materials

6+Ship the Chip

Scissors

Pencils/Pens

Rulers

Digital Scale

Marking pen

Calculator

Clear Adhesive Tape

Masking Tape

Tools and Accessories

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Intactness score :

100: like new, perfect

50 : slightly damaged; cracked but still in one piece

25 : broken in 2 - 5 pieces

5 : broken in 6-20 pieces

1 : broken into more than 20 pieces; crumbled

Ship the ChipScoring

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Intactness ScoreOverall Score

Weight in Kg Volume in cm

8+Ship the Chip

We will imbed the package in the smallest-volume rectangular prism that contains it

We will calculate the volume of the prism; Width x Length x Height For example : 3cm x 4cm x12cm =144 cm3 in the prism

shown below

If your package weighed 100g and had a volume of 800 cm3 and the chip has arrived broken in 3 pieces:

Calculating Volume

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Intactness ScoreOverall Score

Weight in Kg Volume in cm

25_ 0.3125

0.1 800Overall Score

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The engineering behind industrial sorting processes

Exercise 2:

Sort It Out!

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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 Inch 1 Inch 1¼ Inch 1½ Inch

Sort It OutYour Turn

11+Sort It Out

How good is it?

1: “Distance” performance index:

A washer that does not get sorted has maximum Derror = 3

Your Turn

½in 1in 1¼in 1½in1

Distance from correct binhere, Derror = 2 bins

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½

½

½

½

½

1½1¼11 1 1 1¼

1¼1¼

1¼ 1½

1½ 1½

12+Sort It Out

How good is it?

2: “Percentage” performance index:

Your Turn

½in 1in 1¼in 1½in1

11

½

½

½

½

½

1½1¼11 1 1 1¼

1¼1¼

1¼ 1½

1½ 1½

# of washers incorrectly identified

Total # of washers to sort 405%

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Materials: glue, tape, paper or

plastic plates, cardboard, scissors or hole punch, foil, paper, cardboard tubes

washers

Design (draw) a mechanical sorter that can separate the ½in, 1in, 1¼in, 1½in washers

Input: either Parallel – all washers are

inserted at start of your sorter together; or

Serial – washers are inserted at start of your sorter one at a time

Output: Each size of washer in its own physical container

Sort It OutYour Turn

14+Sort It Out

At your table, choose 2 groups to build a parallel sorter; the other 2 groups will build a serial sorter

You will have 45 seconds to allow your sorter to operate

Predict the value of the two performance indices for your design

Construct your sorting mechanism

Test it!

Can you do better?

Your Turn

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All about force and how pulleys can help reduce it

Exercise 3:

Pulleys & Force

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Fixed Pulley Movable Pulley

Pulleys & ForceBasics of Pulleys: Two orientations

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Pulleys & ForceMechanical Advantage

Mechanical Advantage (MA) isthe 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

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Work is the amount of energy transferred by a force acting through a distance

Work = Force x Distance

Work = Force x Distance A bigger mechanical advantage

decreases the force required, but increases the distance over which it must be applied

The total amount of work required to move the load stays the same

Pulleys & ForceWork

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The ratio between Actual and Ideal mechanical advantage is Efficiency

Frictionless system = 100% Efficiency

Pulleys & ForceEfficiency

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Pulleys & ForceMeasuring 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 line

Measure: 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.

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Groups of 2

Develop 2 systems to lift a filled soda bottle 10cm with

1 pulley

2 pulleys

Build your systems

Measure the distance the soda bottle moves and compare it to the distance you had to pull

What 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 bottle

What is the ideal mechanical advantage?

Calculate the efficiency of each system

Pulleys & ForceYour Turn

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Now join with one other group at your table

Develop 2 different systems to lift a filled soda bottle 10cm with all 4 pulleys

Build both systems

What are their actual mechanical advantages? Ideal?

Which one has a better efficiency? Why do think that is?

Pulleys & ForceYour Turn