BPHO Section 1: Annotated Solutions & Topic Breakdown
BPHO Section 1 题目精解与专项突破
After a long July, I finally finished it: a fully topic-classified, fully annotated solutions book for BPHO Round 1 Section 1. What follows is an honest look at what is in it, how it is structured, and why I built it the way I did.
What Is in the Book
The first pages are an Introduction covering the BPHO competition itself, how to use the book, advice for targeting a Gold, and a global problem index with hyperlinks. The index links not just to individual problems but shows how often each topic category has appeared in recent years — useful for triage if you are on a tight schedule.
The body runs over 300 pages — in line with what you would expect from a university textbook in the UK or US. Each topic chapter opens with two subsections before the problems begin: first, a consolidated reference of relevant physics concepts and formulae; second, a discussion of problem-solving strategy specific to that topic type.
The Solution Format
Each problem follows a three-part structure, modelled on the solution presentation in Young's University Physics:
Introduce the physical situation. Translate the problem statement into a cleaner, more tractable form — diagram, variable definitions, key constraints.
Work through the solution in full, step by step, with no gaps. Every line is shown. Problems are solved completely — not "left as an exercise."
Summarise the key idea, note the trap that catches most students, and flag anything worth recording in your own revision notes.
The layout gives the solution text on the left and a wide blank margin on the right — deliberately left empty so students can print and write their own working alongside the model answer. The margin is for your step-by-step attempt; the solution is what you uncover incrementally, not what you read passively.
How to Actually Use It
This matters more than the book itself. Do not open Setup until you are genuinely stuck. Do not open Execute until Setup hasn't unblocked you. Read one line of Execute, put the book down, try the next step yourself, then check. After finishing each problem, record exactly where you stalled and why — that record is the real output of the session.
A Few Features Worth Noting
- Everything is typeset in LaTeX. No scanned handwriting, no illegible official mark schemes, no blurry photographs of someone's notebook.
- Solutions were drafted with the help of AI (after I solved each problem myself), then edited to meet standard physics-language conventions. The language is more precise than what I would write unassisted in a short session.
- Diagrams are drawn throughout wherever a picture genuinely aids the setup or the physical intuition.
- Topic classification is fine-grained enough that both a student just starting BPHO and one drilling specific weaknesses before the paper should find what they need.
Contributing and Collaboration
To keep improving this resource and the wider competition ecosystem, I welcome:
- Alternative solutions, different approaches, corrections, or diagram contributions — especially from students targeting physics-related applications who want a named credit.
- Independent teachers in other subjects (BBO, AMC, and so on) who want to produce a companion volume using the same LaTeX template and AI workflow.
- Print and production partners.