NGSS MS-PS2-2
The Standard
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.
Next Generation Science Standards
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students plan a controlled investigation that changes either net force or mass, not both. They measure one-dimensional motion, record units and a reference frame, and compare the resulting motion changes.
What Mastery Looks Like
- Students identify forces and decide whether they balance. They predict how changing net force or mass affects motion, then plan fair trials with clear variables, measurements, and units.
Common Misconceptions
- Students often think balanced forces mean an object must be stopped, rather than moving at constant velocity. They may confuse one force with net force, or change force and mass together during a test.
How to Assess It
- Exit ticket: Plan three cart trials using a motion sensor to test either net force or mass. Name the changed variable, controls, units, reference frame, and expected motion pattern.
Lesson moves
Ways to Teach It
Use carts, pulleys, washers, and motion sensors to run trials that change pulling force or total mass, one variable at a time.
Write an explanation for why equal pushes change the motion of an empty cart and a loaded cart differently.
Sort force diagram cards into balanced and unbalanced groups, then predict each object's motion relative to a marked reference point.
Compare pushing empty and loaded grocery carts, then explain why the same push produces different changes in speed.
Free download
Printable MS-PS2-2 Worksheet
A ready-to-print activity worksheet aligned to MS-PS2-2, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
Download the worksheetLearning progression
Where This Standard Sits
See the whole path on the Physical Science progression map.
Before This Standard
If students are struggling here, check these first.
What This Unlocks
Mastery here sets students up for these next.
- HS-PS2-3
Understanding how net force and mass change motion supports designing collision devices that reduce force by changing the stopping interaction.
- HS-PS2-1
Middle school force, mass, and motion investigations prepare students to use data to express Newton's second law mathematically.
- HS-PS2-2
Understanding net force and changes in motion prepares students to reason that zero net external force keeps system momentum constant.
Keep exploring
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.
- HS-PS1-3
Plan and conduct an investigation to gather evidence to compare the structure of substances at the bulk scale to infer the strength of electrical forces between...
- 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...
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