STANDARD P3: FORCES AND MOTION Students identify interactions between objects either as being by direct contact (e.g. pushes or pulls, friction) or at a distance (e.g. gravity, electromagnetism), and to use forces to describe interactions between objects. They recognize that non-zero net forces always cause changes in motion (Newton's first law). These changes can be changes in speed, direction, or both. Students use Newton's second law to summarize relationships among and solve problems involving net forces, masses, and changes in motion (using standard metric units). They explain that whenever one object exerts a force on another, a force equal in magnitude and opposite in direction is exerted back on it. (Newton's third law).

P3.p8 Magnetic Force - Magnets exert forces on all objects made of ferromagnetic materials (e.g. iron, cobalt, and nickel) as well as other magnets. This force acts at a distance. Magnetic fields accompany magnets and are related to the strength and direction of the magnetic force.

Science Crime Busters - The objective is to correctly identify the perpetrators of a crime or crimes by using paper chromatography and analysis of unknown solids, liquids, and plastics found at the scene of a crime. Students may also be asked to interpret the results of DNA evidence, identify hair, fibers, shoe prints, tire treads and fingerprints.