Gravity is a force that pulls objects toward the center of a planet, which appears as objects falling "down."

• Construct an explanation of observed relationships (e.g., the distribution of plants in the back yard).

• Use evidence (e.g., measurements, observations, patterns) to construct or support an explanation or design a solution to a problem.

• Identify the evidence that supports particular points in an explanation.

• Analyze and interpret data to make sense of phenomena, using logical reasoning, mathematics, and/or computation.

• Compare and refine arguments based on an evaluation of the evidence presented.

• Construct and/or support an argument with evidence, data, and/or a model.

• Use data to evaluate claims about cause and effect.

• Students routinely identify and test causal relationships and use these relationships to explain change. They understand events that occur together with regularity might or might not signify a cause and effect relationship.

• The effect of unbalanced forces on an object results in a change of motion. Patterns of motion can be used to predict future motion. Some forces act through contact, some forces act even when the objects are not in contact. The gravitational force of Earth acting on an object near Earth’s surface pulls that object toward the planet’s center.