Energy and Forces Interactions:

Knowledge

Forces within an object are internal forces, including tension, compression, shear, torsion. Forces that act on an object from outside the object are external forces, including applied force, friction, elastic or spring forces. External forces cause internal forces within an object. An applied force is exerted on an object by a person or another object.

Friction forces oppose the movement of objects when those objects make contact with other objects or surfaces. Tension is a force exerted by pulling on a string or rope that is connected to an object. Elastic or spring force is exerted on any object that is in contact with a compressed or stretched elastic object or spring. Compression is a force exerted on an object that squeezes, squashes, or compacts the object. Shear is a force that pushes parts of an object in opposite directions, resulting in bending or breaking. Torsion is a force that twists an object.

Knowledge

Plasticity is a property that leads to permanent changes in an object’s shape; e.g., bending a paper clip. Elasticity is a property that enables temporary changes in an object’s shape; e.g., stretching a rubber band.

Knowledge

An action force is exerted on an object in a particular direction. A reaction force acts in the opposite direction of an action force. One object experiences an action force while another object experiences a reaction force in an interaction.

Knowledge

Factors that influence selection of energy resources include

availability and accessibility, societal impacts, economic impacts, environmental impacts.

Knowledge

Responsible management of energy resources includes minimal disruption to nature, restoration of extraction areas, waste management practices, respect for land and resource rights. Some energy resources can be used before processing, such as wood, wind, water. Some energy resources can be used after processing, such as wind, solar, fossil fuels, nuclear, hydro, biofuel. Many energy resources are processed into electricity. Some energy resources can be used before processing and after processing; e.g., wind can be used before processing to sail a boat and after processing as electricity. Energy resources can be used in daily life in various ways, such as heating and cooling, lighting, cooking, transportation.