Top 200 Vocabulary Word List for AP Physics 1 | Must Know Words for Common Examination Instructions

The 200-word examination instruction list

AP Physics 1 questions ask you to calculate, sketch, design or justify. First name the system and choose a direction or axis. Then match the response to the instruction, whether it calls for a force diagram, a measurement plan or a relationship with units.

Start with the list below, or jump to exam requirements, worked examples, the Fencing Method or practice. The list combines command words with terms that tell you how to read a question or format an answer.

Physics instructions, representations and concepts

No.	Instruction or term	Meaning or action
1	Choose a system	State which objects are included before applying a force, energy or momentum relationship.
2	Free-body diagram	Draw and label the forces acting on the specified object or system.
3	Net force	Find the vector sum of external forces on the selected system.
4	Resultant acceleration	Use the direction and magnitude of net force per unit mass.
5	Inertial reference frame	Use a frame in which a force-free object moves at constant velocity.
6	Displacement	Give the signed or vector change in position.
7	Velocity	Give the rate of position change with direction.
8	Speed	Give the magnitude of velocity.
9	Acceleration	Give the rate of velocity change with direction.
10	Constant acceleration	Use kinematics relationships only where acceleration is constant.
11	Position–time graph	Use the slope to find velocity at the requested time or interval.
12	Velocity–time graph	Use slope for acceleration and signed area for displacement.
13	Acceleration–time graph	Use signed area to find change in velocity.
14	Projectile motion	Treat horizontal and vertical components separately with a shared time.
15	Relative velocity	Find velocity with respect to the frame or object named in the question.
16	Weight	Use the gravitational force on the object, with direction toward the source.
17	Normal force	Draw the contact force perpendicular to the supporting surface.
18	Tension	Draw the pulling force along a taut cord or similar connector.
19	Static friction	Use the value needed to prevent sliding up to its maximum.
20	Kinetic friction	Draw friction opposite relative sliding at the contact.
21	Force pair	Identify equal and opposite interaction forces on different objects.
22	Translational equilibrium	Set the net force to zero for the system.
23	Uniform circular motion	Track changing velocity direction even though speed stays constant.
24	Centripetal acceleration	Find inward acceleration from speed squared divided by radius.
25	Radial direction	Resolve the quantity along the line from the centre of rotation.
26	Tangential direction	Resolve along the tangent perpendicular to the radial direction.
27	Work	Find energy transferred by a force acting through displacement.
28	Work–energy theorem	Relate total work on an object to its change in kinetic energy.
29	Kinetic energy	Use one-half mass times speed squared for translational motion.
30	Gravitational potential energy	Compare energies at specified heights relative to a chosen reference.
31	Elastic potential energy	For an ideal spring, use one-half spring constant times displacement squared.
32	Mechanical energy	Add the kinetic and applicable potential energies of the system.
33	Energy transfer	Account for energy crossing the system boundary.
34	Conservation of energy	Account for energy within the system and transfers across its boundary.
35	Power	Find the rate at which energy is transferred or work is done.
36	Momentum	Multiply mass by velocity and keep track of direction.
37	Impulse	Use net force integrated over time, or the momentum change.
38	Force–time graph	Find impulse from the signed area under the net-force curve.
39	Conservation of momentum	Set initial and final total momentum equal when net external impulse is negligible.
40	Elastic collision	Use conservation of kinetic energy as well as the appropriate momentum condition.
41	Inelastic collision	Allow total kinetic energy to change while checking the momentum condition.
42	Perfectly inelastic collision	Assign a shared final velocity to objects that stick together.
43	Centre of mass	Locate the mass-weighted average position of the system.
44	Torque	Use the lever arm and force to find the turning effect about a chosen axis.
45	Lever arm	Find the perpendicular distance from the axis to the force’s line of action.
46	Angular displacement	Give the signed change in angle.
47	Angular velocity	Find the rate of change of angular position.
48	Angular acceleration	Find the rate of change of angular velocity.
49	Rotational inertia	Account for mass distribution relative to the specified rotation axis.
50	Rotational equilibrium	Set net torque about the chosen axis to zero.
51	Rotational kinetic energy	Use one-half rotational inertia times angular speed squared.
52	Angular momentum	For a rigid body rotating about a fixed axis, use rotational inertia times angular velocity.
53	External torque	Identify a turning effect produced by an interaction across the system boundary.
54	Rolling without slipping	Relate centre-of-mass speed to radius times angular speed.
55	Period	Find the time for one complete cycle.
56	Frequency	Find the number of cycles per unit time.
57	Amplitude	Find the greatest displacement from equilibrium.
58	Restoring force	Identify a force component directed back toward equilibrium.
59	Simple harmonic motion	Check that acceleration is proportional to displacement and opposite in direction.
60	Spring constant	Use the proportionality between force magnitude and displacement for an ideal spring.
61	Hydrostatic pressure	Use fluid density, gravitational field strength and depth to find the pressure increase.
62	Gauge pressure	Find the difference between actual pressure and the reference atmospheric pressure.
63	Buoyant force	Relate upward fluid force to the weight of displaced fluid.
64	Archimedes’ principle	Use the displaced fluid’s weight to find buoyant force.
65	Continuity equation	For steady incompressible flow, equate cross-sectional area times speed across sections.
66	Bernoulli’s equation	For steady ideal flow along a streamline, relate pressure, speed and height.
67	Volume flow rate	Find the volume passing a cross-section per unit time.
68	Density	Divide mass by volume.
69	Pressure	Divide normal force by area for a uniformly distributed load.
70	Fluid at rest	Use the hydrostatic pressure relation and buoyancy instead of a flow model.
71	Vector component	Project the vector onto the named coordinate axis with the correct sign.
72	Sign convention	State which direction is positive and use it consistently.
73	Scale drawing	Use the requested scale when converting between arrow length and vector magnitude.
74	Ranking task	Order the listed cases and show equal rankings where warranted.
75	Translate a representation	Preserve the physical relationships when switching between words, equations, diagrams and graphs.
76	Linearise data	Choose transformed axes that yield a straight-line relationship for the proposed model.
77	Qualitative prediction	State how the outcome changes and give a physical reason.
78	Quantitative translation	Use the mathematical relationship to connect a numerical result with a qualitative claim.
79	Experimental design and analysis	Give a repeatable method, then explain how its measurements test the relationship.
80	Mathematical routine	Build the algebra from a relevant principle and show how it answers the prompt.

Laboratory, graph and evidence instructions

No.	Instruction or term	Meaning or action
81	Hypothesis	State a testable prediction about a relationship.
82	Research question	Specify the focused question that the investigation will answer.
83	Independent variable	Identify what the investigator changes deliberately.
84	Dependent variable	Identify the measured outcome of the investigation.
85	Controlled variable	Identify a factor kept constant to help isolate the tested relationship.
86	Control group	Use the baseline comparison to interpret the treatment effect.
87	Experimental design	Use the stated groups, conditions and measurements to judge the experiment.
88	Sample size	Check how many observations, individuals or trials contribute to the result.
89	Random assignment	Use the assignment procedure to assess whether treatment groups support a causal conclusion.
90	Representative sample	Check whether the selected cases reflect the population of interest.
91	Raw data	Use the measurements as originally collected.
92	Processed data	Use values calculated, combined or transformed from the original readings.
93	Outlier	Identify an observation unusually far from the general pattern.
94	Uncertainty	State or interpret the estimated doubt associated with a measurement or value.
95	Error bars	Read their meaning from the figure legend before interpreting them.
96	Repeatability	Consider agreement when the same method is repeated under the same conditions.
97	Reproducibility	Consider whether results agree when the method is repeated under changed conditions.
98	Validity	Consider whether the evidence or method answers the intended question.
99	Reliability	Consider whether a result or method gives consistent findings.
100	Confounding factor	Identify a factor that could contribute to the apparent relationship.
101	Operational definition	Use the measurable rule the study gives for the concept.
102	Correlation	Describe how variables vary together within the data.
103	Causation	Explain how one factor produces a change in another when evidence supports it.
104	Trend	The broad direction or pattern over a range.
105	Pattern	A regularity visible across observations or examples.
106	Scatterplot	Describe form, direction, strength and unusual points when relevant.
107	Line of best fit	Draw a line representing the overall pattern of plotted data.
108	Interpolate	Estimate within the range covered by the data.
109	Extrapolate	Estimate outside the observed range using an assumed pattern.
110	Read the axes	Identify the quantities, units and intervals on a graph before using a value.
111	Gradient from a graph	Calculate change in the vertical quantity per change in the horizontal quantity.
112	Area under a graph	Use the area only where the graph’s quantities make it the requested accumulated value.
113	Baseline measurement	Use the reading taken before the stated intervention or change.
114	Identify the reference group	Find the comparison used to isolate the change attributed to the intervention.
115	Explain a limitation	Identify the assumption or data issue that restricts the conclusion.
116	Keep the comparison fair	Compare quantities on the same stated basis and units.
117	Control treatment	Use the treatment intended to provide a reference comparison.
118	Positive control	Use the comparison expected to show that the procedure can detect an effect.
119	Negative control	Use the comparison expected to show what happens without the target effect.
120	Residual	Subtract the predicted response from the observed response.
121	Significant figures	Give the requested number of meaningful digits.
122	Decimal places	Count the required digits to the right of the decimal point.
123	Dimensional analysis	Track units through the calculation to see whether the result has the requested dimension.
124	Order of magnitude	Estimate the relevant power-of-ten scale.
125	Calculate the percentage change	Divide the change by the starting value and multiply by 100.
126	Rate of change	Find the change in one quantity per unit change in another.
127	Unit rate	Calculate the amount corresponding to one unit of the other quantity.
128	Parameter	Use the fixed or adjustable quantity that defines a family of cases.
129	Model	Use a simplified mathematical or conceptual representation to address the task.
130	Table	Information arranged in rows and columns.
131	Graph	A visual display of data or a mathematical relationship.
132	Diagram	A drawing showing features, structure or relationships.
133	Scale	The intervals or measurement relationship used in a display.
134	Unit	The standard attached to a measurement, such as minutes or metres.

Command words, quantities and exam directions

No.	Instruction or term	Meaning or action
135	Identify	Name the requested item or feature directly.
136	State	Give the requested fact or result in a concise form.
137	Describe	Report the relevant features, sequence or pattern.
138	Explain	Connect the result to a cause, mechanism or principle.
139	Compare	Use the same basis for both cases and state the relevant relationship.
140	Contrast	State a difference between the named cases on a common basis.
141	Determine	Use the information given to reach the requested result.
142	Predict	State the outcome expected under the supplied conditions.
143	Justify	Connect specific evidence or a rule to the answer you give.
144	Calculate	Use the supplied values and the relevant relationship to produce a result.
145	Estimate	Give a reasonable approximate value from the information provided.
146	Interpret	Explain what the result means in the scenario.
147	Analyze	Break the information into relevant parts and explain how they relate.
148	Evaluate	Judge the claim, design or result against a stated or relevant criterion.
149	Support	Give evidence that strengthens the named claim.
150	Select	Choose the option that meets the stated condition.
151	Define	State the meaning of the term with its essential features.
152	Give one	Supply one relevant answer that meets the task.
153	Indicate	Point to or state the feature the prompt asks for.
154	Complete	Fill the missing parts while preserving the given structure.
155	Label	Attach clear names, units or symbols to the requested features.
156	Construct	Produce the specified representation using the information given.
157	Sketch	Show the required shape, relationships and labels.
158	Plot	Place the supplied points on the correct axes and scale.
159	Outline	Give the main steps or features in a logical order.
160	Infer	Draw a conclusion supported by the clues or evidence supplied.
161	Suggest	Offer a plausible answer that fits the scenario and constraints.
162	Distinguish	Name the feature that separates two easily confused ideas.
163	Demonstrate	Show that a stated claim follows by giving appropriate steps or an example.
164	Check	Test the proposed result against the original conditions.
165	Quantify	Give the magnitude of the change or relationship with units where relevant.
166	Represent	Express the same information in the requested form.
167	Evidence	A relevant observation, value, result or example that supports a claim.
168	Claim	A statement that can be tested or supported.
169	Assumption	A condition treated as true for the purpose of the reasoning.
170	Constraint	A restriction the answer must satisfy.
171	Criterion	The rule or standard used to judge whether a choice works.
172	Condition	A requirement or circumstance that affects the conclusion.
173	Conclusion	The result of the reasoning stated in the question’s context.
174	Exception	A case that departs from the stated rule.
175	Counterexample	A case that disproves a general claim.
176	Magnitude	The size of a quantity, considered separately from direction.
177	Direction of change	State whether the quantity increases, decreases or stays unchanged.
178	Initial value	The value at the stated starting point.
179	Final value	The value at the stated end point.
180	Signed change	Subtract the initial value from the final value and retain the sign.
181	Relative change	Divide the difference by the initial value when that baseline is meaningful.
182	Sequence	Give the steps or outputs in their required order.
183	Order of operations	Apply operations in the sequence indicated by grouping and precedence.
184	Exact value	Give the value without rounding or estimation.
185	Approximation	A value or model used as a close representation within stated limits.
186	Unit conversion	Use a conversion factor to change the units while keeping the quantity the same.
187	Ratio	Compare two quantities by division in the order specified.
188	Proportional reasoning	Use the way quantities scale to connect two cases.
189	Direct relationship	As one quantity increases, the other increases under the stated conditions.
190	Inverse relationship	As one quantity increases, the other decreases under the stated conditions.
191	Boundary condition	A requirement that applies at a specified boundary of the system or task.
192	Reference value	A comparison value against which the result is interpreted.
193	Domain	The inputs or values for which the model or operation applies.
194	Range of values	Identify the values between the specified limits and check endpoint inclusion.
195	At least	Includes the named value and every larger eligible value.
196	At most	Includes the named value and every smaller eligible value.
197	Exactly one	Allow one qualifying case and exclude zero and all cases with two or more.
198	Each	Apply the instruction separately to every item named.
199	All	Cover every eligible item in the group.
200	Any	Check whether the wording means one eligible item or any eligible choice.

What the AP Physics 1 exam requires

College Board lists the regular 2027 exam for 5 May 2027. Hybrid digital. Complete multiple-choice items in Bluebook and handwrite free responses in the paper booklet after reading the prompts on screen.

Section	Format and weight
I · Multiple choice	42 questions in 85 minutes, worth 50%. The section includes standalone items and sets tied to a shared stimulus.
II · Free response	4 questions in 95 minutes, worth 50%. There is one question each on mathematical routines, translation between representations, experimental design and analysis, and qualitative/quantitative translation.
Calculator policy	Permitted four-function, scientific or graphing calculators are allowed in both sections. Bluebook provides scientific and graphing Desmos calculators.

AP is a U.S.-based subject examination programme taken by students in the United States and internationally. Practise with the College Board materials for the exact course. If you are taking the exam outside the U.S., confirm registration and local reporting time with your school or test centre. The same vocabulary strategy transfers to other national exams by matching the verb, scope and answer format to that exam’s own sample paper and scoring guidance.

Choose your system before drawing forces. For an explanation, name the law and link it to the observed change. For a graph, label axes with quantities and units, and use slope or area only after checking what the axes represent.

Translate the quantities and preserve the signs

If a force points in the negative direction you chose, show its sign in the equation and its direction in the diagram. A negative acceleration tells you the direction of acceleration. To decide whether the object is slowing down, compare that direction with the direction of the velocity.

Distinguish a slope from an area

Write the units of a proposed slope or area before assigning its meaning. The slope of a position–time graph has units of velocity. The area under a velocity–time graph has units of displacement. On an experimental graph, the units of the slope depend on both quantities you chose to plot.

Use the equations sheet actively

Locate the official equations sheet and practise choosing the equation after naming your system and conditions. An isolated momentum model and a work–energy model can both describe parts of a collision. The requested output and system boundary determine what each relationship tells you.

Worked examples for common exam instructions

Draw and calculate from a force diagram

Prompt. A 2.0 kg cart on a level track is pulled to the right by 8.0 N. A 2.0 N resistive force acts left. Draw the free-body diagram and calculate the acceleration.

Answer. Draw tension right, resistance left, the normal force upward and weight downward. The vertical forces balance. Taking right as positive, the net horizontal force is 6.0 N, so the acceleration is 3.0 m/s² rightward.

Draw only forces acting on the cart. Keep acceleration as a separate quantity rather than adding it as a force arrow.

Translate a graph into motion

Prompt. A velocity–time graph is a straight line from +4 m/s at t = 0 s to −2 m/s at t = 3 s. Determine displacement and state when direction changes.

Answer. Velocity reaches zero at 2 s. The positive area is 4 m and the negative area is −1 m, giving +3 m of displacement. Direction changes at 2 s because velocity changes sign.

If asked for total distance, add the magnitudes of the areas to get 5 m. The same graph supports both answers.

Design an experiment and explain the graph

Prompt. Design a way to estimate the spring constant of a vertical spring within its elastic range.

Answer. Record the unloaded position. Hang several known masses one at a time, wait for equilibrium and measure extension from the unloaded position. Plot mg vertically and extension horizontally. The slope estimates k because the spring force balances mg at equilibrium.

Use several loads to reveal departures from linearity. Specify the axes because reversing them changes the meaning of the slope.

Predict and justify using a relationship

Prompt. An object floats in water and is moved to a denser liquid, where it also floats. Compare the volume displaced in the two liquids.

Answer. The volume displaced decreases. The object’s weight is unchanged, so the buoyant force required for equilibrium is unchanged. In Fᵦ = ρgV, a larger liquid density therefore requires a smaller V.

Name the equilibrium condition before using the equation. It establishes which quantity stays fixed.

Use the Fencing Method to build an answer

Start within a small boundary. Answer one instruction correctly in a short sentence or a small piece of code. Add one detail at a time, checking that each addition helps satisfy the prompt. Finish by transferring the same skill to a nearby case.

Start. The cart accelerates less.

Add context. The mass doubles while the net horizontal force stays the same.

Add the reasoning or operation. Because a = Fnet/m, doubling the mass at the same net force halves the acceleration.

Transfer. Try the same explanation with the mass fixed and the force doubled. Identify the quantity held constant before describing the change.

Practice with the 200 terms

Choose three terms with different answer shapes. Cover the meaning column and say what an examiner would expect to see. Write one answer to each, then underline the exact number, evidence, explanation or code that fulfils the instruction.

Predict versus calculate

Try it. A 0.50 kg cart moving at 4.0 m/s hits a stationary 0.50 kg cart and they stick. Predict whether the pair moves faster or slower than the first cart did, then calculate its speed if net external impulse is negligible.

Check. The joined carts move more slowly. Initial momentum is 2.0 kg m/s and total mass is 1.00 kg, giving a final speed of 2.0 m/s.

On a second pass, change one number or condition and predict how the answer changes before calculating. Then use a released question and its scoring guidelines to check which parts of your reasoning were visible.

Frequently asked questions

Should I use old papers for timing?

Older questions are useful for practising representations and reasoning. For a May 2027 simulation, set the new 85- and 95-minute section limits and use 42 multiple-choice items.

Do I have to memorise every definition?

Use the terms in small groups. For each one, practise identifying the required answer and producing it. The exact instructions and official scoring guidelines for an individual item determine what that response needs.

Official sources and next reading

College Board AP Physics 1 exam format, course description and released questions · College Board AP calculator policy

AP exam command words · eduKateSG vocabulary learning guide · How to build a sentence with the Fencing Method

College Board exam reference materials