Make friction felt first: students rub a socked foot on carpet, then on smooth vinyl, and describe the difference. Introduce friction as a contact force that slows movement when two surfaces rub together — and the key idea that rougher surfaces make more friction.
Frame the investigation with the slide deck: how does the surface affect how far a ball travels? Model completing the top of the Fair Test Investigation Template — question, a reasoned prediction, and the variables (change the surface; measure the distance; keep the ball, the push and the starting point the same). Demonstrate measuring the distance with a tape or measuring wheel.
As a class, agree the method and controlled variables, and choose four surfaces to test (e.g. vinyl, carpet, concrete, grass). Groups roll/kick the ball from the same start on each surface and measure how far it travels, recording in the template's table with teacher check-ins.
Students complete the Friction Investigation worksheet (and the shared template): recording distances, drawing a labelled column graph, identifying which surface had the most friction with data evidence, and evaluating the fairness of the test.
Exit ticket: which surface had the most friction, and how does the data show it?