Some+core+concepts+and+skills

CONTENT FOCUS?
Our draft curricular document states that grade 9 physics has focused on light, sound, and waves. Here are a few of the core ideas I think are worth particular attention:
 * When we draw a nice "wave" on a graph, you have to be careful to pay attention to what the horizontal and vertical axes actually represent. The horizontal axis tends to represent either distance or time. The vertical axis might represent a length/distance (if it is a transverse wave like a water wave) or it might represent pressure (as in a longitudinal sound wave, for example) or it could represent something else (often voltage, for example). It is important to pay close attention to the axes if you want to be able to appropriately interpret the meaning of a sketch/graph of a wave. If students are successful at understanding this big idea, they should be able to manage concepts such as period, frequency, wavelength, speed, and amplitude.
 * For most "normal" waves (i.e. not electromagnetic waves) the wave may move very rapidly in one direction, but without actual transporting any matter in that direction. We say that waves carry "energy" through a "medium". The concept of the medium is especially important, and it makes electromagnetic waves very difficult, conceptually, to make sense of (because, as it turns out, they do not require a medium to propagate through!) Finding out how long it takes a wave to move from one place to another has countless clever applications.
 * How lenses and fiber optics work all boils down to two main concepts: Reflection and, especially, Refraction. Physicists used these concepts long before they were able to explain them (and our present explanations are rooted in quantum physics, which is one heck of a non-intuitive theory, to say the least!) But we are good at describing how these concepts work, and that allows a phenomenal number of wonderful devices.

SCIENTIFIC INQUIRY FOCUS?
What skills are effectively addressed in physics-focused units?
 * Explain **models** with labeled sketches, identification of variables, and identification of assumptions. Aside from the concepts mentioned above, it doesn't matter much what other models students explain, as long as they are explaining //something// from a list of options.
 * Form **expectations** through mathematical problem solving. Students should be able to relate variables such as frequency, period, wavelength, speed, distance, and time for traveling waves. The mathematics behind refraction and interference is too much for 9th graders, but they can make qualitative predictions based on their understanding of the basic concepts. The relationship between light intensity and distance is good to get, as well as the relationships between intensity, power, energy, and cross sectional area. There are also opportunities to explore reflectivity, specific heat, temperature, and radiation. This would help students better understand stories related to global warming and such.
 * Perform **experiments** to investigate the uncertainties associated with any of the mathematical relationships mentioned above. While experiment design could be a part of this, it may be more valuable to provide basic procedures that kids can follow to take data. Then the focus could be on a conceptual exploration of uncertainties involved in measurement and the affect of assumptions behind related models. Form appropriate tables and graphs from **data** collected. **Analysis** of quantitative data related to a mathematical model can include a simple comparison of data with expectations calculated from the (simple) mathematical model. Students taking more advanced math courses can be given more advanced models to examine.
 * The physics-focus in grade 9 provides a good opportunity for the design and testing of instruments. While control of variables is a big deal for the creation of a successful design, the assessment emphasis can be more on the instrument meeting its "initial design specifications". Thus, the outcome need not involve formal graphing of data, as long as this is being addressed in other experiments during the "trimester". Examples of "design and testing" projects could include: Telescopes, Pinhole cameras, many more--see main page

MEETING SCIENCE PHILOSOPHY INTENT AND EAGLES INTENT?
Could we clarify some things here to address these issues?