SC15.PS.12 | ALEX

Science (2015) Grade(s): 09-12 - Physical Science

Constructing Explanations and Designing Solutions

Energy and Matter

Students know:

Energy can be converted from one form to another in a designed system.
Energy can manifest itself in many ways at the macroscopic level such as motion, sound, light and thermal energy.
No system can be 100% efficient.

Students are able to:

Identify the scientific principles that provide the basis for the energy conversion design.
Identify the forms of energy that will be converted from one form to another in the designed system.
Identify losses of energy by the design system to the surrounding environment.
Describe the scientific rationale for choices made for materials and structure of their device in their design plan.
Use results of the tests to improve the device performance by increasing the efficiency of energy conversion.
Determine the component simple machines that make up complex machines such as categorizing a wedge and screw as a variation of an inclined plane; a pulley and wheel/ axle as a variation of a lever.
Explain the relationship between work input and work output for simple machines using the law of conservation of energy. (W = FΔd)
Define and determine ideal and actual mechanical advantage. (IMA = dE/dR AMA = FR/FE)
Define and determine efficiency of machines. (Wout/Win x 100%)
Explain why no machine can be 100% efficient.

Students understand that:

In designing a system for energy storage, for energy distribution, or to perform some practical task, it is important to design for maximum efficiency—thereby ensuring that the largest possible fraction of the energy is used for the desired purpose rather than being transferred out of the system in unwanted ways.
Changes of energy and matter in a system can be described in terms of energy and matter flows into, out of, and within that system.