L3f",null,{"backHref":"/gcse/physics/edexcel/questions","basePath":"/gcse/physics/edexcel/sound-ultrasound-and-infrasound/questions","formulaUrl":null,"initialIndex":46,"initialQuestionWindow":[{"id":"f15dde81-4242-40b9-aef0-d0617a21b2db","revisionId":"3749eee3-86fd-4596-9fb0-9a52e4c3624b","questionNumber":null,"questionType":"LA","specification":"An industrial manufacturing plant installs a protective enclosure around a high-decibel air compressor to minimize noise in the surrounding workshop.","difficulty":3,"difficultyBand":"easy","totalMarks":1,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"b9c62341-9a04-4065-b866-ef1e32c5efa3","label":null,"content":"State **one** modification to the design of the enclosure walls that would decrease the percentage of sound energy transmitted into the workshop.","markscheme":"- Increase the mass or thickness of the enclosure walls (making them harder to vibrate, thereby reflecting more sound energy). B1\n- Line the inside of the enclosure with sound-absorbing materials, such as acoustic foam or mineral wool, to convert sound energy into thermal energy. B1\n- Implement a double-walled construction with an air gap or decoupling layer to create an acoustic impedance mismatch. B1\n- Ensure all joints and gaps in the walls are fully sealed to prevent direct airborne transmission of sound waves. B1","marks":1,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"increase_wall_mass","label":"Increase the wall mass","steps":[{"type":"text","order":0,"title":"Increase wall thickness","content":"Make the enclosure walls thicker or use a heavier material. The greater mass makes the walls harder to vibrate, so more sound energy is reflected and less is transmitted into the workshop. This earns the **B1** mark.","highlights":[{"text":"protective enclosure around a high-decibel air compressor","location":"specification"},{"text":"decrease the percentage of sound energy transmitted into the workshop","location":"specification"}]}]}],"generatedAt":"2026-07-22T11:56:36.448Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"fa9d42a2-53e3-480a-bf56-cae84ed2ea8c","revisionId":"d5aa1d7d-4677-4db6-ab43-05f7700bea2e","questionNumber":null,"questionType":"LA","specification":"","difficulty":4,"difficultyBand":"easy","totalMarks":2,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"f611778c-d975-4115-bbb4-19f9aca9bcd5","label":null,"content":"Describe the difference in frequency between ultrasound waves and infrasound waves.","markscheme":"- States that ultrasound waves have a frequency higher than $20\\,000\\text{ Hz}$ (or $20\\text{ kHz}$), which is the upper limit of human hearing B1\n- States that infrasound waves have a frequency lower than $20\\text{ Hz}$, which is the lower limit of human hearing B1","marks":2,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"hearing_frequency_limits","label":"Compare the frequency limits","steps":[{"type":"text","order":0,"title":"Use hearing limits","content":"Frequency is the number of wave vibrations each second, measured in hertz (Hz). Human hearing extends from $20\\text{ Hz}$ up to $20\\,000\\text{ Hz}$, so use these two boundary values to compare the named waves.","highlights":[{"text":"Describe the difference in frequency between ultrasound waves and infrasound waves.","location":"specification"}]},{"type":"drawing","order":1,"title":"Place both wave types","width":729,"height":237,"shapes":[{"id":"frequency-line","toX":642.5,"toY":138.5,"type":"arrow","color":"black","fromX":82.5,"fromY":138.5},{"id":"frequency-line-rev","toX":82.5,"toY":138.5,"type":"arrow","color":"black","fromX":642.5,"fromY":138.5},{"id":"lower-boundary","type":"line","color":"black","points":[{"x":222.5,"y":194.5},{"x":222.5,"y":82.5}]},{"id":"upper-boundary","type":"line","color":"black","points":[{"x":502.5,"y":194.5},{"x":502.5,"y":82.5}]},{"x":97.2,"y":98

Sound, ultrasound and infrasound

Question 25

Sound, ultrasound and infrasound Questions

Sound, ultrasound and infrasound

Question 25

Sound, ultrasound and infrasound Questions