3-PS2-1
The standard
Plan and conduct an investigation to provide evidence of the effects of balanced and unbalanced forces on the motion of an object.
Next Generation Science Standards
What this standard means
Students need to plan a fair test, push or pull an object, and use what they observe to explain how forces affect motion. They should compare cases where forces are equal and opposite with cases where one side is stronger, in a different direction, or acting alone.
Mastery looks like a student saying, with evidence, why an object stayed still, started moving, stopped, or changed direction. Common sticking points are calling any push a force without thinking about direction, changing more than one variable at once, and thinking balanced forces mean no forces are acting.
Ways to teach it
- Have pairs push a shoebox from opposite sides with equal hands, then with one stronger push, and record the motion after each trial.
- Ask students to write: How do you know forces were balanced or unbalanced in your shoebox test? Use one observation as evidence.
- Show three pictures of a ball being pushed, not pushed, or pushed from both sides, and have students label the force pattern and motion.
- Connect to tug-of-war by asking why the rope sometimes stays still and sometimes moves toward one team.
Plan a lesson for 3-PS2-1
Generate a complete lesson plan aligned to this standard, with objectives, activities, and materials. Free, no account needed.
Related standards
- K-PS2-1
Plan and conduct an investigation to compare the effects of different strengths or different directions of pushes and pulls on the motion of an object.
- 1-PS4-3
Plan and conduct an investigation to determine the effect of placing objects made with different materials in the path of a beam of light.
- MS-PS2-2
Plan an investigation to provide evidence that the change in an object's motion depends on the sum of the forces on the object and the mass of the object.
- MS-PS2-5
Conduct an investigation and evaluate the experimental design to provide evidence that fields exist between objects exerting forces on each other even though th...