IB Physics SL Internal Assessment Example

The investigation is framed around a focused quantitative question with clear variables, control of temperature, and a relevant physical model that gives the work a strong scientific direction.

The student includes several appropriate methodological controls and shows some awareness of why they matter, especially through their preliminary trials and adjustments to the timing region.

The method is broadly reproducible, with a clear sequence of measurements, apparatus details, and repeated trials across multiple sphere sizes.

The theoretical context is strong, but the derivation and justification of the Stokes-law model are not fully developed, especially where assumptions need to be made explicit.

Several important validity conditions are missing or only implied, including Reynolds-number checking, wall effects, fluid behaviour, and verified sphere densities.

The procedure omits enough detail to stop it from being fully reproducible at the highest level, particularly the fluid specification, cylinder dimensions, sphere material/density information, and timing-frame selection.

The raw and processed data are presented in a clear structure, with repeated trials, calculated means, velocities, and uncertainty values that allow the reader to follow the workflow.

The student's processing is generally appropriate for the stated relationship: averaging repeats, calculating speed from distance and time, and plotting velocity against radius squared directly test the predicted trend.

The student shows meaningful awareness of uncertainty, including repeated measurements, error bars, and qualitative sources such as bubbles and temperature variation.

The communication is not fully precise because there are unit inconsistencies and missing calculation details, especially in the way radius is recorded and how uncertainties are propagated.

The uncertainty treatment is incomplete because it does not fully include or justify all relevant sources, such as measurement resolution, frame-rate limits, and uncertainty in the squared radius.

The processing does not fully account for the physical validity of the model, since density values are not reported, and key assumptions like low Reynolds number and wall effects are not checked.