1. Selection of Materials

2. Game! Aim: To make as much money as possible! Make and sell these shapes. All dimensions must be correct or they will not be accepted. 5cm 10 r 20 r 100 r 45 r 6cm

3. Game! 7cm 10 r 20r 100 r 45 r 7cm ColourMaterialCost per sheet (rupees) Green Wood from hillside50 Blue Cut & treated wood from local craftsman 100 Yellow High quality wood from large manufacturer 200 Pink Very high quality synthetic material, global manufacturer 300

4. Selection of Materials

6. Light Cheap Strong enough to withstand expected forces Rigid Durable What qualities are important in your final product?

7. Selection of Materials How can we measure and compare these qualities? - Rupees per kilogram - Kg per m 3 (Density) - Maximum Force (N) per m 2 - Youngs Modulus - Toughness Cost Light/Heavy? Strength Rigid Durable

8. How light is my material? Density is a measure of lightness Density is the mass per unit volume Density (kg/m 3 ) Steel7900 Wood800 Water1000 wood steel water

9. Density Density is the mass per unit volume Do polythene and PVC float or sink? Density (kg/m 3 ) Polythene960 PVC1600 Water1000 Polythene PVC water

10. Density Density is the mass per unit volume I have a mild steel sheet The density is 7900 kg/m 3 1m 2m 0.004 m thick Volume (m 3 ) = x x 1 m 2 m 0.004 m = 0.008 Mass (kg) = x 0.008 m 3 7900 kg/m 3 = 63

11. How rigid is my material? The ‘Youngs Modulus’ is how we measure stiffness 1 N Small Youngs Modulus Low Stiffness Large Youngs Modulus High Stiffness

12. How durable is my material? During manufacture, materials will get small cracks These cracks may get bigger very fast, or very slowly Fatigue crack video The tougher the material, the slower a small crack turns into a big crack steel glass

13. How environmentally friendly is my material? 1)Energy used during manufacture Often extracting a material can use a lot of energy For example extracting aluminium requires a temperature of 2000 o C. This uses up fuel resources, and also large processes need constant supplies of electricity, diverting power away from places such as Pabal.

14. How environmentally friendly is my material? 2) CO2 produced during manufacture When we burn fuel/use electricity we release CO2 CO2 contributes to global warming

15. How environmentally friendly is my material? 3)Recyclability

16. Force on 1 column = / Self Weight = 1,4000N 10,3000N 6 = 1,7000 N Wind Load = 8,9000N How strong must my material be?

17. Force (N/m 2 ) = x Load = 1,7000N 1,7000N 400 x 0.0025 m 2 How strong must my material be? Strength is measured in N per square metre Does this post have a cross section of 1 square metre? 5cm Estimate Area Cross Section = = 0.05m How many 0.0025 m 2 ’s fit into 1 square metre? = / = 1 m 2 0.0025 m 2 400 The force on 0.0025 m 2 is 20,000 N How much force is on 1 m 2 ? 1m is 400 times bigger than 0.0025 m 2 6,800,000 =

18. Strength - Cost 1 4 2 3 6.8 MPa

19. Strength - Cost MaterialStrength-Cost Cast iron2 Low carbon steel2 Medium carbon steel 2 High carbon steel2 Stainless steel Aluminium3 Copper Wood (along grain)1 Wood (across grain) Bamboo1 PVC1 Polythene1 Cement Concrete

20. Density - Cost 1 4 2 3

21. MaterialStrength- Cost Density- Cost Cast iron22 Low carbon steel 22 Medium carbon steel 22 High carbon steel 22 Aluminium32 Wood (along grain) 11 Bamboo12 PVC11 Polythene12

22. Strength - Density 1 4 2 3

23. MaterialStrength -Cost Density- Cost Strength -Density Cast iron223 Low carbon steel 222 Medium carbon steel 222 High carbon steel 222 Aluminium322 Wood (along grain) 111 Bamboo121 PVC111 Polythene121

24. Stiffness - Density 1 4 2 3

25. MaterialStrength -Cost Density- Cost Strength -Density Stiffness -Density Cast iron2233 Low carbon steel 2222 Medium carbon steel 2222 High carbon steel 2222 Aluminium3221 Wood (along grain) 1112 Bamboo1213 PVC111 Polythene121

26. Toughness - Density 1 4 2 3

27. MaterialStrength -Cost Density- Cost Strength -Density Stiffness -Density Toughne ss- Density Cast iron22333 Low carbon steel 22221 Medium carbon steel 22222 High carbon steel 22223 Aluminium32211 Wood (along grain) 11122 Bamboo3213

28. Price (£/kg) Recycle Yes False Recycle - Cost 1 4 2 3

29. MaterialStrengt h-Cost Density -Cost Strengt h- Density Stiffnes s- Density Toughn ess- Density Recycle -Cost Cast iron223331 Low carbon steel 222211 Medium carbon steel 222221 High carbon steel 222231 Aluminium322111 Wood (along grain) 11122

30. Price (£/kg) Energy Required for production (MJ/kg) Price - Energy 1 4 2 3

31. MaterialStren gth- Cost Densi ty- Cost Stren gth- Densi ty Stiffn ess- Densi ty Toug hnes s- Densi ty Recy cle- Cost Ener gy- Cost Total Cast iron 223331115 Low carbon steel 222211212 Medium carbon steel 222221213 High carbon steel 222231214 Alumini um 322111313