Everything Science Grade 12

7.4 CHAPTER 7. MECHANICAL PROPERTIES OF MATTER

Exercise 7 - 3

1. List the similarities and differences between the brittle and ductile modes of fail-
   ure.


2. What is meant by thefollowing terms:

(a) vacancies

(b) dislocations

(c) impurities

(d) grain boundaries

3. What four terms canbe used to describe a material’s mechanical properties?


4. What is meant by thefollowing:

(a) cold working

(b) annealing

(c) tempering

(d) introduction of impurities

(e) alloying

(f) sintering

More practice video solutions or help at http://www.everythingscience.co.za

(1.) 01t5 (2.) 01t6 (3.) 01t7 (4.) 01t8

Chapter 7 — Summary

See the summary presentation ( Presentation: VPnqj at http://www.everythingscience.co.za)

• Hooke’s Law gives therelationship between the extension of a springand the
  force applied to it. The law says they are proportional.


• Materials can be classified as plastic or elasticdepending on how theyrespond
  to an applied force.


• Materials can fractureor undergo creep or fatigue when forces are applied to
  them.