L3f",null,{"backHref":"/gcse/physics/edexcel/questions","basePath":"/gcse/physics/edexcel/sound-ultrasound-and-infrasound/questions","formulaUrl":null,"initialIndex":44,"initialQuestionWindow":[{"id":"ef199e90-1698-4070-956e-b648810bc396","revisionId":"65d6f4c8-34f9-405f-a068-6b0e13a96ffe","questionNumber":null,"questionType":"LA","specification":"A homeowner installs an electronic deterrent near a garden pond to protect the fish from cats. This device emits ultrasound.","difficulty":3,"difficultyBand":"easy","totalMarks":2,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"06b9e7d7-6d3e-4a4e-9265-c93ab9832de6","label":null,"content":"Explain why this device is effective at deterring cats but has no effect on humans.","markscheme":"- States that the frequency of ultrasound (above 20,000 Hz or 20 kHz) is beyond the upper limit of human hearing, so humans cannot hear it B1\n- States that cats have a higher upper limit of hearing than humans, meaning they can detect these high-frequency ultrasound waves B1","marks":2,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"hearing_frequency","label":"Compare hearing ranges","steps":[{"type":"text","order":1,"title":"Compare with humans","content":"Ultrasound has a frequency above $20{,}000\\ \\text{Hz}$, which is $20\\ \\text{kHz}$. This is above the upper limit of human hearing, so humans cannot hear the sound.\n\n**B1:** above the upper limit of human hearing, so humans cannot hear it.","highlights":[{"text":"This device emits ultrasound.","location":"specification"},{"text":"has no effect on humans","location":"specification"}]},{"type":"text","order":2,"title":"Compare with cats","content":"Cats have a higher upper limit of hearing than humans. They can therefore detect these high-frequency ultrasound waves, so the sound can deter them.\n\n**B1:** cats have a higher upper hearing limit, so they can detect the ultrasound.","highlights":[{"text":"effective at deterring cats","location":"specification"}]}]}],"generatedAt":"2026-07-22T11:40:44.861Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"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"}]}]}],"

Sound, ultrasound and infrasound

Question 24

Sound, ultrasound and infrasound Questions

Sound, ultrasound and infrasound

Question 24

Sound, ultrasound and infrasound Questions