ent of friction (A-level only) Flashcards","topicId":"eb350144-7b73-4e08-a816-99f6b3c482b9","topicSlug":"coefficient-of-friction","cards":[{"id":"d17238a8-b514-4cdb-b3f0-86fd17a2bcdc","cardType":"cloze","front":"Friction acts [ ].","back":"Friction acts opposite to the actual or impending motion.","points":null,"mcqOptions":null},{"id":"f9b5e5c8-ac43-4008-b34b-a2916007c12e","cardType":"basic","front":"A block tends to slide down a slope. In which direction does friction act?","back":"Up the slope.","points":1,"mcqOptions":null},{"id":"cb1b64cb-2101-4603-8a28-5350cce56207","cardType":"cloze","front":"The friction model is $\\text{[...]}$.","back":"The friction model is $\\boxed{0\\leq F\\leq \\mu R}$.","points":null,"mcqOptions":null},{"id":"1bb2cd89-bfe4-4f1a-a5d7-db688c95f2d8","cardType":"basic","front":"What does $\\mu R$ represent?","back":"The maximum possible friction.","points":1,"mcqOptions":null},{"id":"b2ce3e58-263b-4efd-8a5d-83cd0f885c0a","cardType":"basic","front":"Why does the coefficient of friction $\\mu$ have no units?","back":"It is a ratio of two forces.","points":2,"mcqOptions":null},{"id":"ec2e9df6-61b8-4739-8b1e-5c394731bb66","cardType":"basic","front":"In the simplified model, how does contact area affect $\\mu$?","back":"It has no effect.","points":1,"mcqOptions":null},{"id":"78203575-a272-4173-a41b-27fba1cd73ae","cardType":"cloze","front":"At limiting friction, $\\text{[...]}$.","back":"At limiting friction, $\\boxed{F=\\mu R}$.","points":null,"mcqOptions":null},{"id":"46e39718-e95e-4fb9-a48d-bacbaf22774b","cardType":"basic","front":"What does limiting equilibrium tell you about a body's motion?","back":"It is at rest but on the point of moving.","points":1,"mcqOptions":null},{"id":"caee48ee-39ff-4981-971c-240927d0b1e6","cardType":"basic","front":"A stationary block requires 8 N of friction and $\\mu R=19.6$ N. What is $F$?","back":"$F=8\\text{ N}$.","points":1,"mcqOptions":null},{"id":"0704531c-640a-4b91-ab44-4298dc1041da","cardType":"basic","front":"When may $F=\\mu R$ be used for a moving body?","back":"When the stated model uses limiting friction for sliding.","points":1,"mcqOptions":null},{"id":"bbced507-6657-4535-a659-62dcdfc213b1","cardType":"basic","front":"When is $R=mg$ valid on a horizontal surface?","back":"When there are no other vertical forces or acceleration.","points":2,"mcqOptions":null},{"id":"ad88e313-1cd6-4346-9f66-b6aa9cb20ea9","cardType":"basic","front":"How does pulling upwards at an angle affect $R$?","back":"It reduces $R$.","points":1,"mcqOptions":null},{"id":"e4331ee5-4336-49b5-8950-d4e6b2260363","cardType":"basic","front":"How does an upward pull affect the maximum possible friction?","back":"It reduces $\\mu R$.","points":2,"mcqOptions":null},{"id":"e91b6637-47f9-4eba-985d-132795955d32","cardType":"cloze","front":"On a slope, the component of weight down the plane is $\\text{[...]}$.","back":"On a slope, the component of weight down the plane is $\\boxed{mg\\sin\\theta}$.","points":null,"mcqOptions":null},{"id":"51753c36-5c54-4f09-9996-f3c08dc66542","cardType":"cloze","front":"On a slope, the component of weight into the plane is $\\text{[...]}$.","back":"On a slope, the component of weight into the plane is $\\boxed{mg\\cos\\theta}$.","points":null,"mcqOptions":null},{"id":"d8109a16-4477-49cd-a228-53675fa33be9","cardType":"basic","front":"With no other perpendicular forces, what is $R$ on a slope of angle $\\theta$?","back":"$R=mg\\cos\\theta$.","points":1,"mcqOptions":null},{"id":"c9ca437c-1d05-4a2e-9b44-020f236866dc","cardType":"cloze","front":"For motion along a slope, Newton's second law gives $\\text{[...]}$.","back":"For motion along a slope, Newton's second law gives $\\boxed{\\text{resultant force}=ma}$.","points":null,"mcqOptions":null},{"id":"18965dfb-032c-4add-a124-

3.3.20 Coefficient of friction (A-level only) Flashcards

3.3.20 Coefficient of friction (A-level only) Flashcards