ath":"/gcse/physics/edexcel/moments-levers-and-gears/questions","formulaUrl":null,"initialIndex":67,"initialQuestionWindow":[{"id":"af765bdd-7084-49cb-88a3-37e56209220c","revisionId":"2d54dbe1-f5c8-4c2f-b02e-0cae46ff5348","questionNumber":null,"questionType":"MC","specification":"The diagram shows an arrangement of four meshed gears in a gear train.\n\n![Four adjacent meshed gears in a horizontal row: Gear A with 16 teeth, Gear B with 32 teeth, Gear C with 24 teeth, and Gear D with 48 teeth.](https://assets.mathsgenie.co.uk/aqa-qb/0d7d6a59-5aec-4b26-a2fe-81af6ae31b60.png)\n\nEach gear turns around a fixed axle. Gear A is rotated at a speed of $4.5\\text{ revolutions per second}$.\n\nWhich of the following options correctly describes the motion of Gear D?","difficulty":5,"difficultyBand":"medium","totalMarks":1,"sourceTitle":null,"calculatorUse":null,"parts":[],"options":[{"id":"0efa7876-ae4e-4fa3-8e22-be17297cb392","content":"speed: $1.5\\text{ revolutions per second}$; direction of rotation: same as A","correct":false,"markscheme":"Incorrect direction of rotation. Having two intermediate idle gears means the output direction is opposite to the input direction.","order":0},{"id":"3d4fb334-4d36-4a55-a344-9327cc022422","content":"speed: $13.5\\text{ revolutions per second}$; direction of rotation: opposite to A","correct":false,"markscheme":"Incorrect speed calculation caused by inverting the gear ratio, multiplying by $\\frac{48}{16}$ instead of $\\frac{16}{48}$.","order":1},{"id":"b142bc85-8560-4fe4-8021-2454d945ac62","content":"speed: $1.5\\text{ revolutions per second}$; direction of rotation: opposite to A","correct":true,"markscheme":"Correct. Each successive meshing gear reverses rotation, meaning Gear D rotates opposite to Gear A. The overall speed ratio is determined solely by the first and last gears: $4.5 \\times \\frac{16}{48} = 1.5\\text{ rev/s}$.","order":2},{"id":"90a053e9-98f0-4610-8449-d871c2e13a92","content":"speed: $13.5\\text{ revolutions per second}$; direction of rotation: same as A","correct":false,"markscheme":"Incorrect speed calculation from an inverted gear ratio combined with an incorrect direction of rotation.","order":3}],"explanation":null,"firstAttemptFullMarks":null},{"id":"c17d3399-7744-48c2-8055-05c8b48db509","revisionId":"11fb21be-bf88-4918-bb51-6a531833e57a","questionNumber":null,"questionType":"LA","specification":"Figure 1 shows a pair of heavy-duty bolt cutters being used to cut through a thick metal rod.\n\n![Bolt cutters cutting a metal rod](https://assets.mathsgenie.co.uk/aqa-qb/b3eb7167-29cd-4231-8a5f-a0c01d5f322a.png)","difficulty":7,"difficultyBand":"medium","totalMarks":6,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"dbcd1378-ef64-4bb4-90af-3527a5936537","label":null,"content":"Explain how the bolt cutters act as a force multiplier to allow a person to cut through the hard metal rod.\n\nYou should include the concept of moments in your explanation.","markscheme":"- States that the bolt cutter acts as a lever system which is a rotational mechanism used to multiply force B1\n- Identifies the pivot as the central hinge pin about which the arms rotate B1\n- States the relationship for a moment: $\\text{Moment} = \\text{Force} \\times \\text{perpendicular distance from pivot}$ M1\n- Explains that the perpendicular distance from the pivot to where the hand squeezes (effort distance, $d_E$) is much larger than the perpendicular distance from the pivot to the metal rod (load distance, $d_L$) A1\n- Explains that a relatively small input effort force over the larger distance $d_E$ creates a substantial turning moment about the pivot M1\n- Concludes that because this turning moment is transmitted to the blades over a much smaller distance $d_L$, a much larger output cutting force (load force) is produced, thereby multiplying the force A1","marks":6,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"moments_force_multiplier","label":"Moments and force multiplication","steps":[{

Moments, levers and gears

Question 27

Moments, levers and gears Questions

Moments, levers and gears

Question 27

Moments, levers and gears Questions