1. Is shop practice based upon any or many sciences?

2. Is it sufficient to know only the practice of the trade to be a successful mechanic?

3. How will it assist a mechanic to know why he performs each operation and uses each tool?

4. Does the average mechanic explain his work in terms of science? If he does not, explain the reasons.

5. Name the branch of science that explains the reasons for the following: iron rust; expansion of a metal by heat; freezing of water; boiling of water; protection of body by rubber gloves in working around electrical machines; finding lead in the form of sulphides in the earth.

6. Of what use to a practical man is a knowledge of the physical properties of water?

7. If the use of a material, such as copper (used in sheet metal tanks and electric wires), is known, is it possible to state its physical properties?

8. What are the physical properties of high-grade sheet metals? Wire? Copper? Lead? Zinc?

9. Give the names and uses of some materials that are: porous; compressible; elastic; soft; hard; heavy; light.