# mami and lauren flash cards

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1. What properties do brittle materials have?
• They don't deform plastically and they can be quite weak when they have cracks in them
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2. What happens to a brittle material when the force increases up to a certain point?
It will suddenly snap
3. Why are ductile materials used for wiring?
Because they can keep their strength when they're deformed
4. What other properties do ductile materials have?
They can change thier shape
5. What's the difference between malleable properties and ductile properties?
Malleable like ductile can change thier shape, however they can lose their strength.
6. What are the three main properties for hard materials?
Hard materials are resistant to cutting, indention and abrasion.
7. What do stiff materials have resistance against?
Stiff materials are resistant to bending and stretching
8. What is stiffness measured by? Also if the value is high what does this mean?
Young modulus. The higher the value the stiffer the material.
9. Why are tough materials difficult to break?
Tough materials absorb a lot of energy making it harder to break.
10. Give three examples of a brittle material?
Cermaics, glass and pottery
11. Give three examples of a ductile material?
Any cable e.g. copper steel etc.
12. What kind of material is gold?
A malleable metal
13. Define the elastic limit?
The elastic point is when a material starts to behave plastically. The material will no longer returnt to its original shape.
14. Define Hooke's Law?
Force is directly proportional to extention.
15. What is the formula for Youngs Modulus?
stress/strain.
16. What is the fomula for strain?
extension/length
17. What is the measurement for strain?
Trick question: There are no units for strain
18. What are the units for Young Modulus?
Nm-2 or Pascals
19. What is the yield point?
Where the material starts to stretch without any extra load
 Author: McAuley ID: 174685 Card Set: mami and lauren flash cards Updated: 2012-10-01 14:29:18 Tags: physics materials Folders: Description: stress, strain ,young modulus ,materials Show Answers: