AP Physics 1 Sub Plans: 4 No-Prep Lessons
Four AP Physics 1 sub plans, one per notice level from no warning to a full day, each built around a no-login interactive that checks itself, so a substitute with no physics background can fill a period and still bring back a written exit task with an answer key.
Draws on interactives spanning Unit 2 Force and Translational Dynamics, Unit 3 Work Energy and Power, and Unit 4 Linear Momentum, so it fits a sub day at any point after forces are introduced rather than one specific unit.
What a physics sub plan actually needs
A sub plan for AP Physics 1 fails for a specific reason: the substitute cannot tell a correct free body diagram from a wrong one, cannot check whether a momentum calculation came out right, and has no way to run lab equipment they have never seen. A plan that survives that has three properties. A student can start it without anyone teaching the content first. It produces something the adult in the room can visually confirm is complete without knowing any physics. And nothing about it requires a lab setup, a formula pulled from memory, or a student account created on the spot.
The four plans below meet all three. Each pairs one of the interactives with a short written task, ordered by how much notice you have.
Before reading further, know what you are choosing between. A worksheet needs someone who knows the answers to grade it. An interactive that marks itself right or wrong needs nobody who knows physics in the room at all, only somebody who can confirm a sheet has five rows filled in rather than one.
No notice at all
You are out with no warning, typing instructions on your phone before the substitute has even arrived. Leave one line.
> Students go to physicslearn.org/interactives/free-body-diagram-builder on any laptop or phone, no account needed. Work through all five scenarios. For each one, guess which forces act and which way they point before checking, then write down every force you got wrong.
That works because the free body diagram builder checks each force by itself and explains the fix, so no adult needs to know a normal force from a tension force. Five scenarios at about ten minutes each, including the write-up, fills a fifty-minute period. A student who finishes early redoes whichever scenario they got most wrong, from memory this time.
An hour of notice
The front office calls an hour before the bell. Project the inclined plane simulator on the room screen and hand out a five-row table with columns for angle, friction, prediction, and result.
Read out five different combinations of ramp angle and friction. For each one, the class writes a guess, stays or slides, before anyone touches the simulator. One student runs that exact setting on the screen, and the class checks its guess against what the tool displays. Five rounds at about six minutes each, with five minutes at the start to explain the format and five at the end for the write-up, covers a forty-minute period without anything left over.
The substitute never has to compute a stays-or-slides answer. The tool shows it on screen for every setting tried.
Half a day of notice
You know at lunch you will not be in for the afternoon block. Hand out the projectile launcher, no account needed, plus a half sheet with three blank predictions and a table for the actual results.
Before dragging the launch arrow, students write their guess for how far the object will land, for three combinations of angle and speed the sub reads aloud. They launch each one, record the actual range, and note in words whether the guess ran too far, too short, or close. Run the first two launches on Earth, then switch the setting to the Moon or Mars for the third and compare the range at the identical angle and speed. That sequence, with the write-up, fills a fifty-minute block.
The closing question does not need a number: why did the low-gravity launch go further with nothing about the throw itself changed. Any answer naming a change in gravity rather than the launch counts.
A full day or a planned absence
With a full day of notice, leave something with two parts and a real written product. Hand out the collision lab, no login, with a recording sheet listing total momentum before, total momentum after, total kinetic energy before, and total kinetic energy after.
Students run five collisions between two carts, sliding the elasticity control from fully elastic to fully inelastic, and copy down the four numbers the tool displays after each run. That takes about twenty minutes. The remaining half of the period is one paragraph: across all five runs, what stayed the same and what changed as the collisions grew less elastic, and why.
The pattern a correct paragraph should show: total momentum matches before and after in every single run, while total kinetic energy matches only in the fully elastic case and falls further as the collisions grow more inelastic. A response naming momentum as unchanged and kinetic energy as dropping, paired that specific way, is right regardless of the exact numbers copied down, which is what makes it markable by someone who has never taken physics.
What to leave in the sub folder
One page, printed, sitting on top of the folder the office already has. It needs four things: the single web address for that day's interactive, written out in full since a substitute will not search for it; the recording sheet or prediction table, already printed in class-set quantities; the plain instructions above, in large type, exactly as written rather than paraphrased; and the timing breakdown, so the sub knows when to move the class from the interactive to the write-up without checking a clock against a lesson plan they cannot otherwise follow.
Test the link yourself before it goes in the folder. A broken or mistyped web address is the single most common way one of these plans fails, and it fails silently: the sub has no way to tell a dead link from a slow one, so the whole period is lost to nobody being sure what to do.
What does not work, and why
A video with a worksheet. Students copy the video into the worksheet without processing any of it, and a non-physics substitute has no way to tell a copied answer from an understood one.
A formula sheet with blanks to fill in. Checking it requires knowing which blank is right, which is exactly the thing the sub does not have.
Anything needing lab equipment set up during the period. Nobody in the room can troubleshoot a photogate or a track that will not stay level, and the interactives above model the same physics with nothing to assemble.
Anything graded on significant figures or units. That is real physics feedback, and it needs a teacher, which defeats the purpose of a sub plan built around not needing one in the room.
Set the no notice plan up before you need it
Write the no notice version now, while nothing is wrong, and put it at the front of the folder. The reason most physics sub plans are weak is not that a good one is hard to design. It gets written at six in the morning by someone who feels terrible and cannot think straight.
One link, one paragraph of plain instructions, one exit task. That is the whole plan, and it holds a class for a full period without anyone in the room needing to know what a free body diagram is.
No notice: the free body diagram trace
You are out with zero warning and are typing the plan on your phone before the substitute arrives.
What to hand out or project: nothing to print if the room has devices. Students open physicslearn.org/interactives/free-body-diagram-builder on any laptop or phone. No account, no setup.
Plain words for the sub to read aloud: work through all five scenarios in order. For each one, guess which forces act and which way they point before checking your answer, then write down every force the tool marked wrong and the fix it gave.
Timing: about ten minutes per scenario including the write-up, five scenarios, fills a fifty-minute period. Early finishers redo their weakest scenario from memory with no help from the tool.
Exit task: one sheet with five rows, one per scenario, each listing the forces missed or reversed and the tool's correction. Answer key: the substitute checks that all five rows are filled in, not the physics itself. A blank row means a scenario was skipped, so send that student back to finish it rather than marking the row wrong.
An hour of notice: stays or slides on the ramp
The office calls with about an hour before the bell.
What to hand out or project: display physicslearn.org/interactives/inclined-plane-simulator on the room screen. Hand each student a five-row table with columns for angle, friction, prediction, and result.
Plain words for the sub to read aloud: I will call out an angle and a friction value five times. Before anyone touches the simulator, write down your guess, stays or slides. Then one student sets that value on the screen and the class checks it.
Timing: five rounds at about six minutes each, five minutes to explain the format at the start, five minutes for the write-up at the end, fills a forty-minute period exactly.
Exit task: for the two rounds a student guessed wrong, one sentence each explaining the miss using the words angle and friction. Answer key: the simulator displays the stays-or-slides verdict on screen for every value tried, so the substitute reads the correct answer straight off the display and never has to calculate it.
Half a day of notice: predict the range
You know at lunch you will not be in for the afternoon block.
What to hand out: the class opens physicslearn.org/interactives/projectile-launcher, no account needed. Give each student a half sheet with three blank predictions and a table for the actual results.
Plain words for the sub to read aloud: before dragging the launch arrow, write your guess for how far it will land, for each of three angle and speed combinations I read out. Launch each one, record the actual range, and write whether your guess ran too far, too short, or close.
Timing: launch the first two on Earth, switch the setting to the Moon or Mars for the third at the same angle and speed, then compare the three ranges. The full sequence with write-up fills a fifty-minute block.
Exit task: one sentence on why the low-gravity launch traveled further with nothing about the throw itself changed. Answer key: weaker gravity keeps the object in the air longer at the same launch angle and speed, so it lands further away. Any response naming a change in gravity, not the launch, is correct; the exact range copied down does not need checking.
A full day or planned absence: momentum versus kinetic energy
You have a full day of notice or a planned absence.
What to hand out: physicslearn.org/interactives/collision-lab, no login, plus a recording sheet with columns for total momentum before, total momentum after, total kinetic energy before, and total kinetic energy after.
Plain words for the sub to read aloud: run five collisions between the two carts, sliding the elasticity control from fully elastic to fully inelastic. After each run, copy down the four numbers the tool shows.
Timing: five runs and the recording sheet take about twenty minutes. The remaining half of the period is the written task below, so nothing else needs preparing.
Exit task: one paragraph on what stayed the same and what changed across the five runs, and why. Answer key: total momentum matches before and after in every run; total kinetic energy matches only in the fully elastic run and falls further as elasticity drops toward fully inelastic. A paragraph naming momentum as unchanged and kinetic energy as falling, in that pairing, is correct regardless of the exact numbers copied down.
Frequently asked questions
What is the best sub plan for AP Physics 1 with no notice?
Send the class to the free body diagram builder with no account needed. Students guess which forces act on each of five scenarios before checking, then write down every force they got wrong. The tool checks each force by itself and explains the fix, so the substitute never has to know a normal force from a tension force, and the written list of misses is evidence you can review later.
Can a substitute with no physics background actually run these plans?
Yes, because each plan pairs an interactive that checks itself with a written task the substitute can confirm is complete without understanding the physics. The sub is checking that a sheet has the right number of filled-in rows, not whether the force diagram or the momentum value is correct. That check is already done by the tool on screen.
Do the AP Physics 1 interactives need a student account or login?
No. The free body diagram builder, inclined plane simulator, projectile launcher, and collision lab all run in a browser with no sign-in and no account. That matters for a sub plan specifically, since a substitute cannot troubleshoot logins for thirty students during a single period.
Why do video and worksheet sub plans fail for AP Physics 1?
Students copy answers from the video into the worksheet without processing them, and a non-physics substitute cannot tell a copied answer from an understood one. The same problem applies to a formula sheet with blanks: checking it requires knowing which blank is correct, which is exactly what the substitute does not have.