MS-PS2-4: Gravity attracts, and it depends on mass
What students must show for performance expectation MS-PS2-4, with a lesson sequence built on live data, the misconceptions to expect, and assessment questions with answers.
Last updated . Curriculum links last reviewed November 2026.
What students must show
Our summary- Students construct and present an argument, using evidence, that gravitational interactions are attractive and depend on the masses of the objects.
Evidence can come from simulations or data on mass, the strength of the pull, distance from the Sun and the time each planet takes to orbit.
Newton's law of gravitation and Kepler's laws.
Our summary, in our own words. Read the official wording.
The three dimensions
Middle schoolEngaging in argument from evidence
Construct arguments backed by evidence and scientific reasoning.
PS2.B Types of interactions
Gravity always attracts; any two masses pull on each other, but the pull is tiny unless one is very massive.
Systems and system models
Models can represent systems and their interactions.
Live tools for this standard
3 toolsLesson sequence
Engage to evaluate- Engage10 min
Ask: does a pencil pull on you? Collect yes and no answers with reasons.
- Explore25 min
Data table: the masses of Earth, the Moon and Mars and their surface gravity (9.8, 1.6 and 3.7 N/kg). Does gravity follow mass exactly? (Not quite: Mars has about a tenth of Earth's mass but more than a third of its gravity, because it is also smaller.)
- Explain20 min
The Weight on other worlds sheet: the same mass weighs different amounts. Then the planets on Deep Space: farther planets move more slowly, so the Sun's pull gets weaker with distance.
- Evaluate15 min
Write an argument: "Gravity always attracts and depends on mass." Use two pieces of evidence, and explain why we never notice a pencil's pull.
Common misconceptions
3 to watch forOnly big things like planets have gravity.
Every mass attracts every other mass; small objects pull far too weakly to feel.
Scientists first measured the pull between lead balls in a laboratory in 1798.
The Moon has no gravity.
The Moon's surface gravity is about one-sixth of Earth's, enough to hold astronauts and dust down.
Work out a weight on the Moon with the Worlds page.
Gravity needs air to work.
Gravity works through empty space; that is how Earth keeps hold of the Moon.
The ISS tracker: there is almost no air up there, yet the path still curves.
Assessment questions
Answers folded awayMS-PS2-4: Gravity attracts, and it depends on mass · orbitalradar.com/schools/us/standards/ms-ps2-4
- Mars has about one-tenth of Earth's mass. Its surface gravity is:
- About one-tenth of Earth's
- About four-tenths of Earth's
- The same as Earth's
- The gravitational force between two objects is:
- Always attractive
- Sometimes repulsive
- Only between planets
- Why do you not feel the pull of your desk?
- An astronaut has a mass of 80 kg. What is it on the Moon?
- Claim, evidence, reasoning: is weight a property of the object alone? Use the Worlds page.
Answer key
- About four-tenths of Earth's (0.38).
- Always attractive.
- Its mass is tiny compared with Earth's, so its pull is far too weak to notice.
- Still 80 kg: only the weight changes.
- No: weight depends on the world's gravity, while mass stays the same.
Worksheet
US LetterOne page on US Letter, filled in with live numbers when you open it. Teacher notes and answers included.
The same idea in state standards
Texas, Florida, Georgia- Texas: 6.7A, IPC 5E
- Florida: SC.6.P.13.2, SC.8.P.8.2
- Georgia: S8P5.a
Related, not equivalent: each state words and groups its standards differently.
More standards pages
Middle schoolAbout these codes
These are our suggestions for where each tool fits. Always preview a page before using it with a class: some tools show ads, these school pages do not.
Codes are performance expectations of the Next Generation Science Standards*, for example 5-ESS1-2. Each summary is our own wording; follow the link on a standard page for the official text.
Suggest a link
Know a better fit for your class, or a topic we have missed? Tell us and we will add it.
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Cite this page
Pick a style, then copy it or download it for your reference manager.Orbital Radar. (2026, November 6). MS-PS2-4: Gravity attracts, and it depends on mass. Retrieved November 6, 2026, from https://orbitalradar.com/schools/us/standards/ms-ps2-4
“MS-PS2-4: Gravity attracts, and it depends on mass.” Orbital Radar, 6 Nov. 2026, orbitalradar.com/schools/us/standards/ms-ps2-4. Accessed 6 Nov. 2026.
Orbital Radar (2026) MS-PS2-4: Gravity attracts, and it depends on mass. Available at: https://orbitalradar.com/schools/us/standards/ms-ps2-4 (Accessed: 6 November 2026).
Orbital Radar. “MS-PS2-4: Gravity attracts, and it depends on mass.” Last modified November 6, 2026. https://orbitalradar.com/schools/us/standards/ms-ps2-4.
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* Next Generation Science Standards is a registered trademark of WestEd. Neither WestEd nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of this product, and do not endorse it.