2019, Question 5 · Short free-response · 7 points · about 13 minutes
Resonating air in an open tube
Find the length of an open tube that resonates with a tuning fork, sketch how the air's maximum speed varies along the tube, and find the new frequency when one end is closed in another gas.
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.
Not in the current course. Every part asks about sound and standing waves in a tube, which the current course no longer includes mechanical waves and sound.
1 Read the question
The question is College Board's, from the 2019 exam. It starts on page 11 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 15, 2025.
Open Question 5 (PDF, page 11)
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 19) What the exam readers saw (Chief Reader report)
Question, scoring guidelines and Chief Reader report: College Board, from the Internet Archive. The title and summary are ours.