2015, Question 1 · Short free-response · 7 points · about 13 minutes
Two blocks over pulleys, adding a third
Draw scaled free body diagrams for two blocks hanging over pulleys, derive the acceleration, and decide how adding a third block on the table changes it.
This exam had five free-response questions in 90 minutes: Questions 1, 4 and 5 were short questions worth 7 points each with about 13 minutes suggested, and Questions 2 and 3 were long questions worth 12 points each with about 25 minutes suggested. The current exam has 4 free-response questions in 95 minutes. The skills these questions practice still count.
Lessons this question draws on
1 Read the question
The question is College Board's, from the 2015 exam. It starts on page 4 of the PDF. College Board no longer posts this exam, so it opens from the copy of College Board's PDF that the Internet Archive saved on May 6, 2026.
2 Write your answer
Answer each part the way you would on the exam, in full sentences, with your work shown. Your writing saves as you type.
3 Score it
Score your answer against College Board's scoring guidelines, one point at a time. Give yourself a point only when your answer says what the guideline asks for.
Scoring guidelines (PDF, page 2) What the exam readers saw (Student Performance Q&A)
Question, scoring guidelines and Chief Reader report: College Board, from the Internet Archive. The title and summary are ours.