AP® Physics 1 Unit 3 Review and Practice Test
Master AP® Physics 1 Unit 3 with quick lessons, clear examples, and exam-style practice on work, energy, and power. Whether you're completing the AP Physics 1 Unit 3 progress check MCQ, preparing for FRQs, or practicing with AP Physics 1 Unit 3 practice problems, UWorld’s AP Physics 1 Unit 3 review gives you the step-by-step support you need to build confidence and improve your score.
Gain Confidence with AP Physics 1 Unit 3 Review
Gain a clear understanding of the most challenging Unit 3 concepts, such as work, energy, and power, through engaging visuals, detailed walkthroughs, and memorable examples. This review gives you everything you need, including realistic AP® Physics 1 Unit 3 practice problems to level up your prep.
Engaging Video Lessons
Learning AP Physics 1 Unit 3 becomes much easier with video lessons that guide you step-by-step through work, energy, and power. Each lesson explains the ideas slowly and clearly, so you can follow along without getting lost. By using these lessons during your Unit 3 review or before trying Unit 3 practice problems, you’ll build stronger confidence for test day.
Interactive Study Guides
Interactive study guides make AP Physics 1 Unit 3 easier to learn by breaking work, energy, and power into simple explanations you can review at your own pace. Each section includes clear notes and visuals. You can use the guides as part of your AP Physics 1 Unit 3 review.
Try AP Physics 1 Unit 3 Real-Exam Style Questions
Question
A block is initially at rest on a horizontal, frictionless surface. A force F is exerted parallel to the block’s displacement and varies over time t, as shown in the graph above. The block moves 1 m during the initial 4 s, then 4 m from t = 4 s to t = 6 s. What is the average power delivered to the block between t = 0 s and t = 6 s?
| A. 1 J/s | |
| B. 3 J/s | |
| C. 8 J/s | |
| D. 12 J/s |
Explanation
The work (W) done on an object is equal to the net force (F) applied to the object, multiplied by the distance (d) the object moves, and the cosine of the angle (θ) between the force and displacement vectors:
The applied force transfers energy to the object, which produces changes in the object's kinetic energy and, if applicable, the system's potential energies.
Power (P) is the rate of energy transfer in a system. The average power delivered to an object is defined as the total amount of work done on the object over a time interval ∆t:
The average power applied to the block can be determined from the data in the graph. From 0 s to 2 s, the block experiences zero force and zero work is imparted to the block. Subsequently, from 2 s to 4 s, a 2 N force moves the block 1 m. The work done over this time is:
Next, from 4 s to 6 s the force increases to 4 N and the block moves 4 m:
Hence, the total work delivered to the block between 0 s and 6 s is:
(Choices A and C) 1 J/s and 8 J/s are the individual power values delivered from 2 s to 4 s and 4 s to 6 s, respectively.
(Choice D) The total area under the curve is 12 N∙s, which does not have the correct units for power (J/s).
Things to remember:
Power is the rate of energy transfer. Average power is calculated from the amount of work done on an object over time.
Question
A block of mass m slides across a frictionless surface with a speed v until it collides with a spring that is initially uncompressed. At the instant the block comes to rest, the compressed spring exerts a force F on the block, as shown in the figure above. The spring is then reset, and the experiment is repeated with a second block of mass 4m and speed v/4. What is the maximum spring force required to stop the second block?
| A. | |
| B. | |
| C. | |
| D. |
Explanation
The work W done on an object is equal to the net force (F) applied to the object, multiplied by the distance (d) the object moves, and the cosine of the angle θ between the force and displacement vectors:
Furthermore, the work-energy theorem states that the net work done on an object equals its change in kinetic energy, ΔKE:
In addition, Hooke's law implies that a spring exerts a force Fs with a magnitude that is proportional to, and in the opposite direction of, the displacement from equilibrium x of the spring:
In this question, the spring force varies linearly in magnitude from 0 to F as the spring compresses. Hence, the work Wnet on the block is equal to the area beneath the graph of force as a function of position (i.e., the area of the triangle):
As a result of the negative work done by the spring on the block, the KE of the block decreases to zero:
Combining the two previous equations:
Since :
The ratio of the force F2 on a block of mass 4m moving with a speed v/4 to the force F1 on a block of mass m moving with a speed v yields:
Therefore, the maximum spring force required to stop a block with mass 4m and initial velocity v/4 is F/2.
(Choice A) A spring force that is independent of the mass of the block would have a magnitude of F/4, but the spring force also depends on mass.
(Choice C) A KE that is proportional to v would result in a spring force F, but KE is proportional to v2, not v.
(Choice D) A spring force that is independent of the speed of the block would have a magnitude of 2F, but the spring force also depends on v.
Things to remember:
According to the work-energy theorem, the work done on an object equals its
change in kinetic energy. The force exerted by a compressed spring is
proportional to the displacement of the spring from equilibrium. The area
beneath a graph of force as a function of position equals work.
Question
The graph of kinetic energy as a function of time for an object dropped from rest and falling through the air is shown in the figure above. The net work done on the object from t = 0 s to t = 1.2 s is most nearly equal to which of the following?
| A. The slope of a line connecting the origin and the point on the graph at 1.2 s | |
| B. The area under the curve between the origin and 1.2 s | |
| C. The value of the graph at 1.2 s | |
| D. The slope of the tangent to a best-fit line at 1.2 s |
Explanation
The work W done on an object is equal to the net force F applied to the object, multiplied by the distance (d) the object moves, and the cosine of the angle θ between the force and displacement vectors:
Furthermore, the work-energy theorem states that the net work done on an object equals its change in kinetic energy, ΔKE:
In this question, the change in kinetic energy ΔKE of the falling object can be determined from the graph as the difference between the final and initial kinetic energies. Since the initial KE equals zero:
Moreover, the net work done on the object equals the change in kinetic energy:
Therefore, the net work equals the value of the graph at t = 1.2 s (ie, the final kinetic energy):
(Choice A) The slope of a line connecting the origin and the point on the graph at 1.2 s represents the average power exerted on the object, not the net work done on the object.
(Choice B) The area beneath a graph of kinetic energy as a function of time does not have meaning in this context.
(Choice D) The slope of the line tangent to the curve at 1.2 s represents the instantaneous power exerted on the object, not the net work done on the object.
Things to remember:
The work-energy theorem implies that the net work done on an object equals
its change in kinetic energy. The change in kinetic energy (and the net work
done) can be found from the initial and final data points on a graph of
kinetic energy as a function of time.
Study Anywhere, Anytime
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Frequently Asked Questions (FAQs)
What are the main topics covered in AP Physics 1 Unit 3: Work, Energy, and Power?
AP Physics 1 Unit 3 covers the core ideas behind how energy moves and changes in physical systems. Understanding these concepts helps you make sense of real problems involving motion, forces, and power. This unit is important because it connects directly to many AP-style questions and real-life examples.
Main topics include:
- Translational kinetic energy: The energy an object has because of its motion.
- Work: The transfer of energy that occurs when a force acts over a distance.
- Potential energy: Energy stored within a system due to its position or configuration.
- Conservation of energy: The principle states that the total energy of a system remains constant.
- Power: The rate at which work is done or energy is transferred.
UWorld makes learning these ideas much easier with clear explanations and AP Physics 1 Unit 3 practice problems that match the real exam. It’s a simple way to study smarter and feel confident with every part of your Unit 3 review.
How should I prepare for an AP Physics 1 Unit 3 exam?
Preparing for the AP Physics 1 Unit 3 exam starts with reviewing the core ideas of work, energy, and power at a comfortable pace. Since these topics build on each other, it helps to begin with simple explanations and then practice applying the formulas in different situations. Studying a little each day will make the concepts stay with you longer.
A good approach is to read through your AP Physics 1 Unit 3 review notes and watch video lessons that show each concept step-by-step. After that, try solving a mix of AP Physics 1 unit 3 practice problems and MCQs so you can test your understanding. This helps you recognize patterns and common question styles.
UWorld is a great resource for this because it gives you clear explanations and realistic questions that match the difficulty of the exam. Working through these examples strengthens your problem-solving skills and makes it easier to feel confident when you take your Unit 3 test.
Are any free resources available for AP Physics 1 Unit 3?
Yes, there are several free resources you can use to start studying for AP Physics 1 Unit 3. These can help you review the basics of work, energy, and power before you move on to deeper practice. Using a mix of reading and watching examples can make the concepts easier to understand.
The College Board offers free practice questions and progress checks that match the style of the real exam. You can also use Khan Academy for simple video lessons and step-by-step explanations, which help build your foundation before trying harder problems. Both are great for quick AP Physics 1 unit 3 review sessions.
If you want more realistic, exam-level practice, UWorld gives you high-quality AP Physics 1 Unit 3 MCQ practice problems with clear explanations. It’s an easy way to strengthen your understanding and feel ready for the real test.
What types of questions are on the AP Physics 1 Unit 3 test?
The AP Physics 1 Unit 3 test includes several different question styles that check how well you understand work, energy, and power. You’ll need to show your ability to read graphs, apply formulas, and explain how energy moves in a system. The exam mixes math, concepts, and reasoning.
You can expect a combination of AP Physics 1 unit 3 MCQ, short written responses, and situations where you must analyze motion or forces. Many tests also include AP Physics 1 Unit 3 FRQ, where you explain your thinking clearly and use correct units and steps. Some questions involve diagrams or comparing different energy changes.
UWorld helps you get ready for all these formats with realistic practice questions and simple explanations that show how to approach each type. Working through these examples strengthens your problem-solving skills and makes your unit 3 AP Physics 1 review more effective.
How can I improve my score on the Free-Response Questions (FRQs) for Unit 3?
Improving your FRQ score for AP Physics 1 Unit 3 starts with understanding the key ideas behind work, energy, and power. FRQs often ask you to explain relationships, show each step, and apply formulas correctly, so practicing clear writing and organized solutions is important. Start by reviewing the core rules and learning how to connect energy changes to motion.
To get better, try rewriting solved examples in your own words and checking how high-scoring answers explain their reasoning. Working through the AP Physics 1 Unit 3 FRQ items and related practice problems helps you build confidence and identify common question patterns.
UWorld makes this easier by giving you FRQ-style questions with step-by-step explanations that show how to structure strong responses.
What is the "Work, Energy, and Power" unit's weight on the AP Physics 1 exam?
The “Work, Energy, and Power” unit usually makes up an important part of the AP Physics 1 exam. While the exact percentage can change slightly each year, Unit 3 generally takes up about 18–23% of the test. Because these ideas connect to motion, forces, and graphs, the College Board uses them in both multiple-choice and free-response sections.
You’ll see Unit 3 concepts appear in AP Physics 1 Unit 3 MCQs, graph analysis questions, and FRQs where you explain energy changes or calculate work. Many Unit 3 AP Physics 1 practice problems on study sites reflect this same balance.
UWorld helps you focus on the parts of Unit 3 that show up most often. Their clear explanations and realistic questions make your AP Physics 1 Unit 3 review more efficient, so you can feel confident with this heavily weighted section on test day.
Where can I find a good study guide for AP Physics 1 Unit 3?
Finding a good study guide for AP Physics 1 Unit 3 starts with looking for resources that explain work, energy, and power in simple steps. A helpful guide should show examples, break down formulas, and give you clear ways to connect each idea to real exam questions. This makes your studying feel more organized and less overwhelming.
You can check trusted AP prep sites, teacher-made notes, or free online summaries that cover the full AP Physics 1 Unit 3 review. Many students also like using video-based guides to understand how each formula works in different problems. Just make sure the guide covers both concepts and problem-solving practice.
If you want structured support, UWorld offers explanations and AP Physics 1 Unit 3 practice problems that match the real test format. Their study materials help you understand each step clearly, making your Unit 3 AP Physics 1 prep smoother and more effective.
Can I find practice tests specifically for AP Physics 1 Unit 3?
You can absolutely find practice tests tailored for AP Physics 1 Unit 3, focusing on work, energy, and power. These tests give you a feel for the real exam format and help you identify what concepts you’ve nailed and which ones still need work. Using targeted Unit 3 materials makes your review far more effective than generic physics practice.
Specifically, the platform UWorld offers AP Physics 1 practice tests that align with the official exam structure and include a wide range of topics, including those in Unit 3. Their library features exam-style MCQs and FRQs where you’ll solve real-world problems on energy conservation, work done by forces, and power calculations. Each question comes with detailed explanations that break down not just what the answer is but why it’s correct.
If you want to boost your confidence ahead of the exam, UWorld’s Unit 3-specific testing materials are a smart move. They simulate real test conditions, track your progress, and teach you to think like the AP exam wants you to, so you’ll walk in ready and calm, not scrambling.
What formula sheet should I use when studying AP Physics 1 Unit 3?
Using the right formula sheet makes AP Physics 1 Unit 3 much easier to study because this unit relies heavily on equations for work, kinetic energy, potential energy, and power. A good formula sheet keeps everything in one place so you don’t waste time searching for the right expression during practice. It also helps you get familiar with the symbols and units used on the test.
Look for a sheet that includes labeled formulas, small example diagrams, and reminders of when each equation applies. Reviewing it while solving AP Physics 1 unit 3 practice problems helps you memorize the structure without forcing it. The more you use it, the faster you’ll recognize what each problem needs.
UWorld supports this by showing formulas directly in solutions and explaining when and why each one is used. Their step-by-step breakdowns make your AP Physics 1 Unit 3 review easier because you learn how to connect each formula to real exam-style questions. This builds confidence and helps you move faster on test day.
What common mistakes should I avoid when studying AP Physics 1 Unit 3?
A lot of students make Unit 3 harder than it needs to be by rushing through formulas without understanding what each variable means. Since this unit focuses on work, energy, and power, skipping the basic ideas can make the problems feel confusing. Spending time on simple examples first helps you build real confidence.
Another common mistake is avoiding mixed problems where energy changes in more than one step. Practicing AP Physics1 unit 3 MCQs and multi-stage questions helps you see how energy transfers and forces interact in real situations. Reviewing your errors is just as important as getting answers right.
UWorld makes this process easier by giving you AP Physics 1 unit 3 practice problems with explanations that show exactly where mistakes happen. With clear reasoning and step-by-step solutions, you learn to fix small errors before they cost you points on test day.