Hooke’s Law – Hanging Masses Simulation
Description
This Hooke’s law simulation is a hands-on virtual lab for students meeting elasticity and springs for the first time. It reproduces the real load-and-measure experiment rather than a slider on a screen: you mount a spring on the stand, hang slotted masses on it one at a time, and read the spring’s length off a fixed ruler. The spring constant is never displayed, so the value of k has to be measured, not read off.
Components
The simulation includes:
- A rack of five springs, labeled A to E, each with a different stiffness and its own elastic limit
- A set of slotted masses: a 10 g hanger, two 20 g, two 50 g and one 100 g piece
- A fixed 20 cm ruler with its zero at the upper end of the spring, so the reading is the spring’s total length
- A magnifier that follows the spring’s pointer and enlarges the millimeter divisions
- Springs that can be permanently deformed, then loaded and unloaded to measure what they keep
- A step-by-step guided tutorial that can be opened at any point without disturbing the current setup
How the experiment works
The 10 g hanger goes on first, because the other masses stack on it, exactly as at the bench. For every load the student records the spring’s total length, subtracts the no-load reading to obtain the extension, and converts the hanging mass into the force pulling on the spring. Plotting force against extension gives a straight line whose gradient is the spring constant. Three of the five springs give readings that land exactly on a millimeter division; the other two do not, so the same law has to be found through less convenient arithmetic.
Beyond the elastic limit
Each spring can be loaded until it yields. A spring pushed past its elastic limit stretches further than the law predicts and keeps part of that stretch for good: unload it and it settles at a new, longer length instead of returning to its original one. Every spring keeps a different amount, so groups comparing damaged springs get different results. This also makes the laboratory method available: load, read, unload, check that the spring recovers, and repeat until one load leaves it permanently longer. The elastic limit is then bracketed between the heaviest load the spring survived and the one that ruined it.
Learning Outcomes
Students measure extension, calculate tension from a hanging mass, and deduce for themselves that force is proportional to extension within the elastic limit. They also meet the boundary of the law directly, by finding it rather than being told it. Suitable for intermediate physics classes and for elasticity units taught in a virtual lab setting, and aligned with the Grade 9 load-and-measure lab sheet. No value of g is imposed, so the class can work with 9.8 or 10 N/kg as the teacher prefers.