Your responses show a clear, accurate understanding of how physical properties produce sound and how ratios describe musical relationships. You correctly explained that different objects vibrate at different frequencies because of size, shape and tension, and that combining those frequencies creates musically pleasing intervals. You identified that ratios describe relationships between two quantities and applied this to frequencies, noting that a 2:1 ratio is an octave. Naming Pythagoras and describing the monochord as a single-stringed instrument used to compare pitches and measure ratios was excellent.
Strengths: accurate terminology (frequency, ratio, octave), concise explanations, good historical connection. This work demonstrates exemplary beginner achievement: you can connect mathematical ideas to musical outcomes and use evidence from the clip.
Targets to deepen learning: give one concrete example (e.g., a string half the length vibrates at twice the frequency), sketch a simple monochord diagram or label parts, and try measuring or calculating a 3:2 ratio (a perfect fifth) from sample frequencies. Next steps: complete a short experiment with a string or tuning app to record two frequencies and write the ratio, then reflect on how it sounds. Keep using precise language and add small experiments to move from understanding to application. Well done, continue.