AP® Physics C - Mechanics - Section II Free-Response Questions - Version J

Q: What drag model is used for the box in Question 1?

The resistive force is modeled as FR = -bv, where b is a positive constant and v is the box’s velocity.

Q: When does the cube begin to slide downward in Question 1?

At t = tcrit, the cube begins to slide downward along the wall; before that time it remains in contact at a constant height.

Q: How does Question 2 change the projectile after the highest point?

At the highest point, the projectile breaks into two pieces: piece Q of mass M and piece R of mass 3M, and their subsequent motion determines their landing locations.

Sep 20, 2026

Uploaded by Aditya

AP® Physics C: Mechanics Section II free-response exam (Version J) presents problem-solving tasks on classical mechanics, including motion with resistive forces and friction. Question 1 analyzes a box with a sliding cube under a drag force modeled by FR = -bv, requiring derivations of acceleration, the cube’s normal force over time, and friction-force graphs, plus determining the time when the cube starts to slide down. Question 2 examines projectile motion with a midair break into masses M and 3M, requiring momentum-based reasoning to connect breakup timing and landing positions.

LanguageEnglish

CategoryExam

FormatPDF

Pages12

Reading Time30 min

AccessFree to download

Section II - Time

Question 1 - Version J

Question 2 - Version J

2026 AP® Physics C: Mechanics Free-Response Questions © 2026 College Board. College Board, Advanced Placement, AP, AP Central, and the acorn logo are registered [trademarks of College Board. Visit College Board on the web: collegeboard.org](trademarks of College Board. Visit College Board on the web: collegeboard.org). AP Central is the official online home for [the AP Program: apcentral.collegeboard.org](the AP Program: apcentral.collegeboard.org). PHYSICS C: MECHANICS SECTION II TIME – 1 HOUR AND 40 MINUTES Directions: Section II has 4 questions and lasts 1 hour and 40 minutes. You may use the available paper for scratch work and planning, but only work written in the freeresponse booklet will be scored. Any work done on scratch paper will not be scored. Label parts (e.g., A, B, C) and sub-parts (e.g., i, ii, iii) as needed. Use a pencil or a pen with black or dark blue ink to write your responses. A calculator is allowed in this section, as well as a ruler and straightedge. You may use a handheld four-function, scientific, or graphing calculator, or the calculator available in this application. Reference information, including lists of equations, can be used throughout the exam. A digital version is available in this application. All final numerical answers should include appropriate units when applicable. Credit for your work depends on demonstrating that you know which physical principles to apply in a particular situation. Credit will be awarded only for work that is clearly designated as the solution to a specific part of a question. Credit also depends on the quality of your solutions and explanations. Therefore, you should show your work for each part in the space provided for that part. If you need more space, be sure to clearly indicate where you continue your work. When constructing a graph or diagram, use only one color of ink or pencil. You may pace yourself as you answer the questions in this section, or you may use these optional timing recommendations: It is suggested that you spend about 25 minutes each on Questions 1 and 3, about 30 minutes on Question 2, and about 20 minutes on Question 4. You can go back and forth between questions in this section until time expires. The clock will turn red when 5 minutes remain—the proctor will not give you any time updates or warnings. Note: This exam was originally administered digitally. It is presented here in a format optimized for teacher and student use in the classroom. During the AP Exam administration, students have access to reference information. To see the reference information for this course, please visit AP Central: [https://apcentral.collegeboard.org/exam-administration-ordering-scores/administering-exams/](https://apcentral.collegeboard.org/exam-administration-ordering-scores/administering-exams/)[ ](https://apcentral.collegeboard.org/exam-administration-ordering-scores/administering-exams/)[subject-specific/reference-information](subject-specific/reference-information) Question 1: Version J 1. A box of mass M slides to the right on a horizontal surface. A small cube, also of mass M, is inside the box. The cube is against the right wall of the box and above the bottom of the box, as shown in Figure 1. The coefficients of static and kinetic friction between the cube and the wall of the box are ns and nk , respectively, where ns > nk . Figure 1 The speed of the box is decreasing as a result of a resistive force that is exerted on the box. The resistive force FR is modeled by FR = -bv , where b is a positive constant and v is the velocity of the box. Friction between the box and horizontal surface is negligible. Consider the motion of the box and cube for the following times. • At time t = 0 , the box-cube system slides to the right with speed v0 . • For 0 \# t < tcrit , the cube remains in contact with the wall of the box at a constant height above the bottom of the box. • At t = tcrit , the cube begins

FAQs

What drag model is used for the box in Question 1?

The resistive force is modeled as FR = -bv, where b is a positive constant and v is the box’s velocity.

When does the cube begin to slide downward in Question 1?

At t = tcrit, the cube begins to slide downward along the wall; before that time it remains in contact at a constant height.

How does Question 2 change the projectile after the highest point?

At the highest point, the projectile breaks into two pieces: piece Q of mass M and piece R of mass 3M, and their subsequent motion determines their landing locations.

Sep 20, 2026

Uploaded by Aditya