TED622-2Pinkleton

== =Constructivist or PBL Plan: Water Power!=

**Lesson Topic: Water Power!** **Grade level:8** **Length of lesson: 1 hr 15 min**

**Stage 1 – Desired Results** || **1.08, 2.04, 3.02, 3.07, 3.08** || **Can water do work?** **How?** || Students will be able to:
 * **Content Standard(s):**
 * **Vocabulary:**
 * **kinetic energy**
 * **potential energy**
 * **hydroelectric power** || **Essential Question(s):**
 * **Student objectives (outcomes):**
 * Explain how we can harness the energy of water to do work.
 * Identify pros and cons of hydroelectric power.
 * Explain the difference between kinetic energy and potential energy ||
 * **Stage 2 – Assessment Evidence** ||
 * **Performance Task(s):** || **Other Evidence:**

Short quiz--See p. 3 ||
 * **Stage 3 – Learning Plan** ||
 * **Learning Activities (day 1):**
 * 1) **WARM UP**

**Materials: 14 ziploc bags (7 filled with corn meal, 7 with corn kernels),** **picture of water wheel if needed:** __[|**http://www.planetware.com/picture/boston-boston-surroundings-us-ma387.htm**]__

**Write on board:** 1)Can water do work? How?

2)Brainstorm with your neighbors for five minutes and then write your answers on the index card (1 per group).

(Hint 1: look at the baggies on your desks.)

(Hint 2: picture on board)

**Discuss answers briefly. Remind students of the flood video viewed on Wednesday and the power of the flood waters as they smashed cars and trucks into trees and each other.**

**III) View Prezi on dams and hydroelectric power (potential energy/kinetic energy/mechanical energy/electrical energy):** __[|**http://prezi.com/dmbcqp8pav5j/edit/#23_5119899**]__
 * 1) **Students read p.130-133 in textbook. Any questions?**

**IV) Videos:**

**Hydroelectric Power (3 min. each):** __[|**http://www.youtube.com/watch?v=wvxUZF4lvGw&feature=related**]__

__[|**http://www.youtube.com/watch?v=cEL7yc8R42k**]__

**Hoover Dam (8 min):** __[|**http://www.cbsnews.com/video/watch/?id=6881732n**]__

**Three Gorges Dam (6 min):** __[|**http://video.nytimes.com/video/2007/11/17/world/1194817102562/living-with-the-three-gorges-dam.html**]__

**Discuss (as a class) the pros and cons of hydroelectric power, both in terms of human cost and the environment.** ||

**__Reflection/Justification Water Power! Lesson Plan__**

I gave each group of 3-4 students a bag of corn kernels and a bag of corn meal and asked them (with their neighbors) to puzzle (Lambro, Chapter 2: “students are attracted to scenarios of mystery and intrigue”) out the following: Can water do work? How? I also brought up a picture of a water wheel/mill on the overhead projector, and reminded them of the video we had watched the previous day of the floodwaters in Queensland tossing cars and trucks around like corks (“exposure to multiple sources of information”, Windschitl). My hope was that the students would make the connection that we use the power of falling water to grind the corn into meal (mistake #1: eighth graders do not care about corn meal, or corn kernels, unless they have been, or are about to be, made into popcorn) and then apply or superimpose this knowledge on a new situation: that of falling water (in a dam)being used to turn a turbine to generate electrical power. The biggest problem was that even with the “hint” (the picture on the overhead projector of a mill with a water wheel, “resource anticipation”, Lambro, Chapter 4), most of my students did not have this context or prior knowledge—most simply did not know that these mills for thousands of years were how we ground corn into meal or wheat into flour. I'm not sure many of them knew that flour is ground from wheat. So, the major reasons my lesson was a flop were that A) I failed to provide engaging visual/tactical aids, and B) I misjudged the amount of prior knowledge my students had relative to mills and water wheels.

My thinking was this: that by having them construct the knowledge that we use the power of water to grind corn (I was looking for a fairly simple, familiar, everyday example with the water falling on the wheel and turning the wheel to do work) which could then be applied to an unfamiliar situation: that of the falling water (in the dam) turning the turbine to produce electricity. BUT since the water wheel/mill is not really part of what we term “common knowledge” for this group (I suspect this is generational as opposed to cultural) it just didn't work. So I pretty much ended up telling them what the connection was and then we had a brief discussion about water and its power, followed by a brief reading and a presentation (I've included the link). I also thought it might be good to provide a scientific definition of “work” (“work is done whenever an object is pushed or pulled through a distance”) and demonstrated this by pushing the stool across the floor (work) and pushing against the wall (not work since the wall doesn't move).

Another problem with my lesson was that since we are getting a little pressed for time (at this point I know my OSTE is getting concerned about covering the rest of the material that the kids are likely to be tested on), I only had one day to talk about hydroelectric power, which is really not enough. What she wanted them to get out of it was clarification of the concepts of potential energy and kinetic energy (of water), and since this section was included as part of the water unit in our textbook (as opposed to a unit on electricity, or different methods of supplying our power needs and their impact on the environment) I felt that I had to gloss over these more interesting (I think) aspects of the topic. Which was too bad, since I did have kids engaged and asking questions, especially about how the electricity is actually generated by a dam (you mean you rotate giant magnets next to copper wire and that makes electricity?) and about things like how many people were displaced (a million) in the area of the Three Gorges Dam (Lambro: kids like ethical issues/current events with a “controversial dimension”). I //have// noticed that students enjoy discussing different sides of an issue, in this case, the Chinese need for sustainable, clean power balanced against the many people whose lives were altered for the worse by having to make way for the dam (this would be a good “engage” activity next time I do hydroelectric power).