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--- course_planning:184_projects:s18_project_13 [2018/04/10 16:34] – created tallpaul
+++ course_planning:184_projects:s18_project_13 [2018/04/12 16:40] (current) – dmcpadden
@@ Line 1: / Line 1: @@
-==== Need for Speed:  Project 13A ====
+==== Project 13A: The Fast and the Curious ====
 Thanks to the research that folks at the Hawkion facility were able to do on the EM-boar tigers, the people of Lakeview have been able to set up a scientifically supported protection system. They have installed a giant magnet into the cliffs nearby, and it is aligned in such a way that there is a constant (practically speaking)  $5 \text{ mT}$  magnetic field directed into the ground near Lakeview and the surrounding area. The hope is that the field will ward off the EM-boar tigers and keep the people of Lakeview safe.
@@ Line 6: / Line 6: @@
 {{ 184_notes:12b_engine_voltmeter.png?700 |Manny's Engine}}
+==== Project 13B: Clean Source of Energy or Hidden Stash of Jellybeans??? ====
+{{ 184_notes:13a_picture.png?700 |Alternative Energy Source}}
+The people of Lakeview are starting to get used to living life in the magnetic field, now that it seems to be doing a pretty good job keeping EM-boar tigers from entering the town and causing mayhem. Local alternative energy scientist Alysson Watersa has even installed a source of clean energy that is made possible by the magnetic field. She has constructed a water mill with her bare hands and situated it into the side of the cliff, conveniently below a waterfall so that the motion of the water turns the mill at a frequency of  $15 \text{ rpm}$ . Dr. Watersa also fixed a board along the axle of the mill, and she has laid a loop of 12-Gauge copper wire (with a radius of  $1 \text{ m}$ ) on the board. One end of the loop becomes a wire that comes out the side of the board and is grounded into the cliff. The other end of the loop becomes a wire that runs out the other side of the mill, all the way back to Lakeview. As the mill turns, so does the loop, causing a current to exist in the wire, which can be used as a small convenience for the good people of Lakeview.
+Unfortunately, local superstitious person Manny Hallabero is causing a ruckus about the new energy source. He claims that it's all hocus pocus, and Dr. Watersa is just using the water mill as a ploy to hide her stash of jellybeans in the face of the cliff in order to avoid sharing. He won't listen to Dr. Watersa for even a second, so it's up to you to explain to Manny how the water mill works and why it produces the current that it does. It may be helpful for Manny to see a diagram of the mill and a graph of the current produced. Be as detailed as possible, as Manny can be very stubborn about changing his mind. Dr. Watersa's blueprints, shown below, may be helpful.
+{{ 184_notes:13a_representation.png?600 |Diagram}}
+<WRAP info>
+=== Learning Goals ===
+  * Calculate the induced current from a changing magnetic flux
+  * Use the right hand rule to determine the direction of the induced current
+  * Explain why induced current is different from the current in a circuit (in other words, what does it mean for a current to be "induced"?)
+  * Explain why there is a negative sign in Faraday's Law
+</WRAP>