Use these targets, vocabulary, rubrics, examples, and score sheet with the instructor's approved lesson and procedure. This is an assessment companion, not a complete lesson or safety authorization.
Student lessons, data, and public practice answers (not assessment keys): Unit 08 learning pathway.
The student demonstrates the following:
Five science criteria plus separately reported integration (Page 3).
Measure the buoyant force; compare to displaced fluid.
The student predicts float or sink and explains why (Page 4).
Weights, displaced volume, and buoyant force kept distinct.
You are making a decision, not adding up points. For each criterion, decide whether the work is Developing, Proficient, or Mastery — the column language tells you which. A criterion counts as mastered only when the student can both take the measurement and defend why it floats. Each student has three tokens per term; each token retries one rubric criterion. Approved accommodations, equipment failures, and approved absences are handled separately and do not consume these tokens.
Accept listed synonyms; use the distinction column to resolve near-matches.
| Term | Accepted explanation | Distinction |
|---|---|---|
| Density | Mass per volume | Use the relevant body or fluid density and compatible units. |
| Pressure | Normal force per area | Pressure and force are not the same quantity. |
| Gauge / absolute pressure | Relative pressure / pressure from vacuum | Add the common reference to gauge pressure for absolute pressure. |
| Hydrostatic difference | rho g depth for the stated model | Assumes stationary fluid with constant density and g. |
| Pascal’s principle | Applied pressure change is transmitted | Include height differences and actual piston losses separately. |
| Buoyant force | Weight of displaced fluid | Use submerged volume, not automatically complete body volume. |
| Floating equilibrium | Buoyancy equals weight | For freely floating rest without other vertical support forces. |
| Apparent weight | Support force for the immersed body | Weight minus buoyancy in the stated stationary model. |
| Continuity | A v is constant for this flow | Steady incompressible stream without a branch or leak. |
| Bernoulli model | P + rho v^2/2 + rho g z | Steady incompressible flow along a streamline; no pump or significant losses. Height matters. |
| Criterion | Developing | Proficient | Mastery |
|---|---|---|---|
| Density & pressure | Confuses mass with density or force with pressure. | Computes each but not how pressure changes with depth. | Uses density and hydrostatic pressure with compatible units; distinguishes force, gauge pressure and absolute pressure. |
| Buoyancy & Archimedes' principle | Thinks heavy things always sink. | States Archimedes' principle but cannot apply it to predict floating. | Predicts float or sink from the weight of displaced fluid and defends the reasoning quantitatively. |
| Pascal's principle | Does not see how pressure transmits through a fluid. | Knows a hydraulic lift multiplies force but not why. | Explains Pascal's principle and how a hydraulic system trades distance for force at equal pressure. |
| Fluid flow | Ignores that speed and area are related in flow. | Recalls that narrowing speeds flow but not the pressure consequence. | Calculates continuity and Bernoulli pressure with elevation, stated streamline/loss assumptions and a bounded interpretation of discrepancies. |
| Lab technique (buoyancy measurement) | Estimates buoyancy by eye with no measurement. | Weighs an object in and out of water but does not compare to displaced volume. | Measures the buoyant force and the displaced fluid and verifies Archimedes' principle with uncertainty. |
| Integration (cross-domain) | Makes no supported connection between the source and the science. | Uses the source but needs help connecting evidence, writing, or limitations to the science. | Independently connects History, Reading, and Writing using a cited source, appropriate evidence, a limitation, and a scientific explanation. |
The split between Proficient and Mastery is displaced fluid: a mastered student explains floating by the weight of water pushed aside, not by “heavy” or “light.” Ask “how much water does it push aside, and what does that weigh?”
Read these before you grade. They show what Mastery and Developing actually sound like, plus the edge cases where you should coach rather than decide on the spot.
Evidence for the score sheet: Level: ______ Case/data: ______ Criterion: ______ Source/date: ______ Work/graph: ______ Assumptions/uncertainty: ______ Transfer: ______. Attach the independent attempt; practical observation is separate.
Student: ______________________________________ Date: _______________ Guide: _________________________
| # | Criterion | Decision | Notes |
|---|---|---|---|
| 1 | Density & pressure | Dev / Prof / Mast | |
| 2 | Buoyancy & Archimedes' principle | Dev / Prof / Mast | |
| 3 | Pascal's principle | Dev / Prof / Mast | |
| 4 | Fluid flow | Dev / Prof / Mast | |
| 5 | Lab technique (buoyancy measurement) | Dev / Prof / Mast | |
| 6 | Integration (cross-domain) | Dev / Prof / Mast |
☐ No ☐ Yes — for criterion: __________
Tokens left this term after this session (choose one): ☐ 3 ☐ 2 ☐ 1 ☐ None left
Dev = Developing · Prof = Proficient · Mast = Mastery · Unsure between two levels? Circle the lower one and note what a re-do would need.