In this unit we study systems and how energy flows and is conserved as well as what causes matter to change.
Energy's role in systems
1.2.1. Analyze how systems function, including the inputs, outputs, transfers, transformations, and feedback of a system and its subsystems.
Describe the function of a system's parts or subsystems. Explain inputs, outputs, transfers, transformations, and feedback of matter, energy, and information in a system.
1.2.2. Analyze energy transfers and transformations within a system, including energy conservation.
Describe and determine the energy inputted to an object as work (i.e., work on an object is the product of the force acting on the object and the distance the object moves as the force acts).
Describe how a machine transfers work and transforms force and distance through a force-distance trade-off (e.g., a small force acting over a long distance can be transformed to a large force acting over a short distance).
Examine and explain how energy is transferred within and among systems.
1.3.3. Analyze the factors that affect physical, chemical, and nuclear changes and understand that matter and energy are conserved.
Investigate and analyze the effect of different factors on the rate of a physical and chemical change (e.g., temperature, surface area, pressure, catalysts). Explain how chemical changes produce substances with different chemical properties and the same total mass. Describe the products of radioactive decay in terms of the conservation of matter and energy (e.g., a radioactive nucleus decays into a new nucleus and emits particles and rays). Recognize and explain that the rate of radioactive decay of a substance is constant, not affected by any factors (e.g., the half-life of a radioactive substance is constant over a long time and a wide range of conditions found on Earth).