One thing that stood out to me was the incorporation of each of the six-simple machines: lever, wedge, wheel and axle, screw, incline plane, and pulley. Check out the attached pictures and see if you can identify simple machines. Remember, all machines are in essence one or more simple machines in combination. Also, focus your memory to the calculation for the mechanical advantage for each machine. For a hint, the general formula is MA = F output/ F input; a machine multiplies the output force or torque applied.
Please note the cutting tool in the last picture. The edge is, of course, sharp. Yet, we as students of physics should looking a little closer. Let us consider pressure (P). Quantitatively, pressure is force divided by area - P = F/A. The sharpness of the cutting tool used on the glass actually accounts for a dramatic increase in applied pressure. Think of it. If the surface area of the tool is decreased ( sharpened) a greater pressure is generated mathematically. This also explains why a sharp knife ( small area) is better at cutting your steak than a dull knife ( big area).
Great tie in with physics and the use of pressure with the example of a steak knife. Dinner today must of been the inspiration to the latter part of the post. Thanks for posting.
ReplyDeleteThanks for your update to the blog. I know that the things we are learning this week will have an impact in your classroom this fall.
ReplyDeleteYour force ratio equation was explained well and thought provoking.
ReplyDeleteGreat application of our experience there to the calculation of force for simple machines.
ReplyDeleteYou come up with connections to physics wonderfully! Great use of science.
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