1.In terms of thermal expansion, why is it important that a lock and its key be made of the same material or of similar materials? 2. Why are incandescent bulbs typically made of very thin glass? 3....

1.In terms of thermal expansion, why is it important that a lock and its key be made of the same material or of similar materials? 2. Why are incandescent bulbs typically made of very thin

glass? 3. For many years, a method for breaking boulders was putting them in a hot fire and then dousing them with cold water. Why would the boulders fracture? 4. An old technique for separating a pair of nested wedged-together drinking glasses is to run water at different temperatures into the inner glass and over the surface of the outer glass. Which water should be hot and which cold?