Why a checklist before every lab
A physics bench is the one place in a high-school education where a careless step can actually hurt someone. Launched projectiles strike, loaded springs snap back, and an unsecured mass swinging free does not forgive inattention. A pre-lab checklist is not bureaucracy — it is the routine that makes safe, prepared work automatic, so that on the day an experiment goes sideways the student's hands already know what to do.
It also does something quieter: it forces the student to arrive ready. The most dangerous lab partner is the one who skimmed the procedure in the hallway. This checklist closes that gap. Print one for every experiment, work top to bottom, and do not release a single cart or spring until the last box is checked.
The goal is not to follow rules. It is to walk to the bench already knowing the hazards, the steps, and the result you expect.
1 — Safety
Nothing below this section happens until everything in it is done. No exceptions, every lab, every time.
- Impact-rated safety glasses on — over the eyes, not pushed up on the forehead — whenever springs or projectiles are in play.
- Long hair tied back and loose sleeves or drawstrings secured away from moving carts, springs, and pulleys.
- Closed-toe shoes; no bags, cords, or loose clothing in the runway or under the bench.
- The apparatus inspected for every experiment in use — pinch points, spring tension, and launch direction noted before anything is loaded.
- The runway and launch path clear — no people, bags, or obstacles anywhere a cart or projectile could travel.
- First-aid kit located, and you know where to stand clear of a launch or a swinging mass before you start.
- Return bins identified — you know exactly where each cart, mass, and timer goes when you finish.
2 — Setup
With safety confirmed, build the bench so the work flows without scrambling mid-run.
- The full procedure read end to end — not skimmed — so you know what step comes next.
- All apparatus gathered — track, carts, timers, masses, string — clean and laid out in order of use.
- Photogate, stopwatch, spring scale, or meter stick selected to match the precision the step requires.
- Track leveled and photogates aligned; you know which times and distances you need to record and to how many decimal places.
- Slotted masses located, values double-checked against the procedure, and secured to the cart or hanger.
- Ring stands, clamps, and pulleys set up and stable — nothing free to swing, slip, or topple once loaded.
- Lab notebook open to a fresh, dated page with the title and question already written.
3 — Readiness: the pre-lab questions
This is the section that separates a technician from a physicist. Before the first measurement, the student should be able to answer these in writing — in the lab notebook, in their own words.
- What is the question? State, in one sentence, what this experiment is trying to find out or measure.
- What is the physics? Write the governing equation (or the key relationship) the experiment depends on.
- What is my prediction? A specific, numerical expectation — the approximate time of flight, the expected final velocity, the sign and rough size of the acceleration.
- What am I measuring, and in what units? Name every quantity you will record, its unit, and its uncertainty.
- What could go wrong? Identify the one or two steps most likely to introduce error, and how you will minimize them.
- What does success look like? Know, before you begin, what a reasonable result would be — so an absurd number raises a flag at the bench, not a week later.
A student who answers all six is not guessing their way through a recipe — they are running an experiment they understand, with a result they can already roughly predict. That is exactly the readiness the lab-notebook entry is built to capture, and the kind of preparation a lab defense is designed to reward.