Saturday, May 8, 2010
Like any good science book, this one has lots of everyday applications that the students can relate to. Can you guess the mechanical principle from the examples given?
1. "[...] common examples are the oar of a rowboat and the potato-ricer."
2. " When we use a wringer, turn a door-knob, or draw water from a well with a windlass, we are doing work with the help of a _________________ ."
3. "The propellers that pull flying boats and aeroplanes through the air are ____________. Even the snowmobile, which travels swiftly over the deep snow that blocks other motor traffic, is propelled by an ___________."
4. " [...] the binder, the fanning-mill, the sheaf-loader, and the grain-separator."
Give up yet?
1. The lever
2. Wheel and axle
3. Air screws
4. Inclined plane
Aside from noticing how common, everyday examples have changed so much, it's also interesting to notice the change in language over the past 70 or so years, most noticeably the de-hyphenization of words such as door-knob.