stions","basePath":"/gcse/physics/edexcel/newton-s-laws-and-momentum/questions","formulaUrl":null,"initialIndex":95,"initialQuestionWindow":[{"id":"bc4f86c0-1ad2-4a74-bfd4-8f4de9c65b7c","revisionId":"56510ae1-b5b2-4a5f-a132-f1b5d3039649","questionNumber":null,"questionType":"LA","specification":"An Antarctic research expedition uses a heavy snow utility vehicle to tow a chain of cargo sleds across flat, icy terrain at a constant velocity, as shown in the diagram below.\n\n![Cargo sleds being towed by a snow vehicle](https://assets.mathsgenie.co.uk/aqa-qb/4bc7f866-bafa-4fac-bc40-2fa65ddcb86f.png)\n\nThe sleds are connected in series by magnetic hitch couplings, which release if the tension force pulling them exceeds a certain threshold.\n\nAs the team adds more cargo sleds to the rear of the train (to the left of Sled D), they notice that when the total number of sleds is increased, the magnetic coupling between Sled B and Sled C suddenly releases, splitting the train.","difficulty":7,"difficultyBand":"medium","totalMarks":2,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"793b3fbb-5ada-4b06-8b5c-162f41e79205","label":null,"content":"Explain, in terms of forces, why the coupling between Sled B and Sled C breaks when additional sleds are added to the rear.","markscheme":"- Identifies that adding more sleds to the rear increases the total friction/resistive force acting on all the sleds behind the coupling (Sled C, Sled D, and any subsequent sleds). M1\n- Explains that at constant velocity, the tension in the coupling between Sled B and Sled C must balance this total resistive force (or that the required pulling force increases); once this required tension exceeds the maximum magnetic force of the coupling, it breaks. A1","marks":2,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"force_balance","label":"Balance the forces","steps":[{"type":"text","order":1,"title":"Consider the rear sleds","content":"The coupling between B and C pulls the **rear section**: Sled C, Sled D and every sled added behind them. Each additional sled has its own friction (a resistive force opposing the motion), so adding sleds increases the total resistive force on this rear section. This earns **M1**.","highlights":[{"text":"adding more cargo sleds to the rear of the train (to the left of Sled D)","location":"specification"}]},{"type":"text","order":3,"title":"Explain why it breaks","content":"The increased total resistance means the required tension in the B–C coupling increases. Since the sleds move at constant velocity, the tension must balance the total resistive force on the rear section. **This earns A1:** when the required tension exceeds the coupling’s maximum magnetic force, the coupling breaks.","highlights":[{"text":"at a constant velocity","location":"specification"},{"text":"the magnetic coupling between Sled B and Sled C suddenly releases","location":"specification"}]}]}],"generatedAt":"2026-07-22T11:56:20.025Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"cf179164-f050-4f46-a878-6c3505c0f9c5","revisionId":"adf12825-9ba8-4759-8ce9-ce531ff6f0cb","questionNumber":null,"questionType":"LA","specification":"An electric buggy accelerates at a constant rate of $2.15 \\text{ m/s}^2$ along a flat test track.\n\nThe net force acting on the buggy is $1.840 \\text{ kN}$.","difficulty":4,"difficultyBand":"medium","totalMarks":3,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"39393f57-c07d-4556-a29c-b63ea3c9e156","label":null,"content":"Calculate the mass of the buggy.\n\nGive your answer to three significant figures.","markscheme":"- Converts the net force to Newtons: $1.840 \\text{ kN} = 1840 \\text{ N}$ B1\n- Rearranges Newton's second law to $m = \\frac{F}{a}$ or substitutes values into $F = ma$ M1\n- Calculates the mass as $856 \\text{ kg}$ (to three significant figures) A1","marks":3,"order":0,"markingRubric":null,"explanation":{

Newton's laws and momentum

Question 31

Newton's laws and momentum Questions

Newton's laws and momentum

Question 31

Newton's laws and momentum Questions