Changes in an object's motion are dependent on the mass of the object and the sum of the forces acting on it.

• Conduct an investigation and/or evaluate and/or revise the experimental design to produce data to serve as the basis for evidence that meet the goals of the investigation.

• Collect data to produce data to serve as the basis for evidence to answer scientific questions or test design solutions under a range of conditions.

• Collect data about the performance of a proposed object, tool, process or system under a range of conditions.

• Use mathematical representations to describe and/or support scientific conclusions and design solutions.

• Create algorithms (a series of ordered steps) to solve a problem.

• Apply mathematical concepts and/or processes (e.g., ratio, rate, percent, basic operations, simple algebra) to scientific and engineering questions and problems.

• Construct an explanation that includes qualitative or quantitative relationships between variables that predict(s) and/or describe(s) phenomena.

• Construct a scientific explanation based on valid and reliable evidence obtained from sources (including the students' own experiments) and the assumption that theories and laws that describe the natural world operate today as they did in the past and will continue to do so in the future.

• Apply scientific ideas, principles, and/or evidence to construct, revise and/or use and explanation for real-world phenomena, examples, or events.

• Apply scientific reasoning to show why the data or evidence is adequate for the explanation or conclusion.

• Students explain stability and change in natural or designed systems by examining changes over time, and considering forces at different scales, including the atomic scale. Students learn changes in one part of a system might cause large changes in another part, systems in dynamic equilibrium are stable due to a balance of feedback mechanisms, and stability might be disturbed by either sudden events or gradual changes that accumulate over time.

• The role of the mass of an object must be qualitatively accounted for in any change of motion due to the application of a force.