STEM REASONING AND EVIDENCE WORKBENCH
Calculate point-particle angular-momentum magnitude from mass, radius, and tangential speed and audit learner products.
Review output
Load the worked example to inspect realistic inputs, or enter anonymous classroom or laboratory evidence. Results remain in this browser tab until you copy or download them.
Transparent method
Angular momentum vector is position vector crossed with momentum. Its magnitude is L equals m r v sine phi, where phi is the angle between radius and velocity. This bounded workbench assumes perpendicular tangential motion, so sine phi equals one and L equals mass times radius times speed. Units combine as mass times distance squared per time. Supported means the learner magnitude matches the perpendicular point-particle product within tolerance. A disagreement can come from omitted mass, radius rather than diameter, inconsistent units, a nontangential velocity, or arithmetic. Even a correct magnitude leaves direction, selected origin, system boundary, torque, uncertainty, and conservation evidence for human review.
Confirm the question, approved source, units, notation, signs, response coding, model assumptions, and review threshold. Keep an unchanged copy of measurements or learner evidence.
Run the worked example, inspect every intermediate row, and compare the result with a hand calculation, diagram, representation, periodic table, or approved laboratory method.
Record the method, assumptions, uncertainty, units, classifications, and flagged rows. Verify the editable report independently before instruction, assessment, or laboratory use.
How to interpret the result
Use for point masses moving tangentially about a selected origin when learners need to connect mass, lever arm, speed, and angular momentum. The planner does not calculate a rigid body moment of inertia, resolve a general three-dimensional cross product, preserve vector direction, determine torque, choose the origin, test conservation, include relativistic effects, or validate experimental sensors.
A two-kilogram marker at radius one half metre moving three metres per second has magnitude three. A half-kilogram orbit model at radius two and speed four has magnitude four. A 1.2-kilogram point at radius one quarter and speed ten also has magnitude three. The review model should give six rather than the entered five.
Angular momentum vector is position vector crossed with momentum. Its magnitude is L equals m r v sine phi, where phi is the angle between radius and velocity. This bounded workbench assumes perpendicular tangential motion, so sine phi equals one and L equals mass times radius times speed. Units combine as mass times distance squared per time.
Supported means the learner magnitude matches the perpendicular point-particle product within tolerance. A disagreement can come from omitted mass, radius rather than diameter, inconsistent units, a nontangential velocity, or arithmetic. Even a correct magnitude leaves direction, selected origin, system boundary, torque, uncertainty, and conservation evidence for human review.
Do not use diameter as radius, drop mass, confuse angular speed with tangential speed, add factors instead of multiplying, ignore the sine factor for nonperpendicular motion, omit the chosen origin, or call a magnitude positive proof of conservation. Draw radius and velocity vectors, apply the right-hand rule, check dimensions, and compare initial and final systems carefully.
Learning boundary
This browser-local workbench applies only the disclosed rules. It cannot diagnose a learner, certify an experiment, establish a chemical structure, or replace teacher, laboratory, and safety judgment.
Review checklist
Practical questions
No. Processing occurs in the current browser tab. Avoid personal information and retain authoritative records only in the school-approved system.
No. It describes entered evidence under one disclosed rule. Compare several evidence sources and ask for reasoning before drawing a conclusion.
Treat it as an editable calculation aid. Show your own reasoning, cite required sources, and follow the course method and academic-integrity rules.
YOUR NIRMION
