Experimental procedures in AP physics, the redesigned free response section, and Wally the Astronaut

Wally the Astronaut, from The Physics Aviary

Above is a screenshot from the "Work to KE" simulated laboratory exercise on The Physics Aviary. In the exercise, you press start, and a fire extinguisher causes Wally the Astronaut to speed up.  You press stop, and the fire extinguisher ceases to apply a force.  Wally coasts, then passes through two photogates separated by 10 meters.  The time for Wally to cross the photogates is displayed.

You can do a thousand different sorts of classroom exercises with this single simulation.  I like to give this quiz here, go over the quiz, then have students go through this laboratory exercise. But the simulation here is so, so rich, you could do many different things.  Propose your favorite in the comments!

I was asked how I would describe* an experimental procedure on the AP physics 1 exam.  Some teachers ask their students to write a step-by-step instruction manual, including safety procedures and calculation instructions, for an in-class laboratory exercise.  Is that what the AP exam demands?  Should a procedure include calculational instructions?

*The "task verbs" on the AP physics exams will be in boldface as of the 2025 administration.

Historically, the AP readers expect students to communicate what they measured, and how they measured it.  If the experiment could in fact be done in a reasonable high school laboratory, the procedure is legit.  

The prompt on the AP exam - especially the redesigned 2025 AP exams - will be more targeted than what I often see in classroom lab handouts.  For example, the exam might write:

(a) Students are asked to take measurements to create a graph that could be used to determine the mass of Wally.  Describe an experimental procedure that the students could use to collect the data needed to determine Wally's mass. Include any steps necessary to reduce experimental uncertainty.

My response might be, "Measure the force F exerted by the fire extinguisher with a scale.  Then in each of many trials, turn off the fire extinguisher after Wally has traveled a distance d, a different distance in each trial.  Measure d; and divide the 10 m photogate distance by the time output of the photogate to find Wally's speed v."

The analysis - that is, how to do the necessary calculations - is usually in a separate lettered part of the question.  It's fine generally to write the analysis part in the same section as the procedure!  But the procedure will earn points independent of the analysis.  One being wrong or incomplete doesn't affect how the other will be scored.

Part (b) might ask about the analysis:

(b) Describe how the data collected in part (a) could be plotted to create a linear graph and how that graph would be analyzed to determine Wally's mass m.

And I'd say, "Wally's kinetic energy is equal to the work done by the fire extinguisher, .  [That first sentence is probably not necessary for credit!  But I write it so it's clear where my analysis comes from.]  Plot the work done by the fire extinguisher (Fd) on the vertical axis; plot (1/2)v^2 on the horizontal axis.  The slope will be Wally's mass."

Full credit would be earned for a more bare-bones "Plot Fd on the vertical axis, and v^2 on the horizontal.  The slope is (1/2)m."