hat the chemical energy store of the battery decreases, transferred electrically and mechanically, with some dissipated as thermal energy due to friction and air resistance B1\n- **Section B:** Identifies that the kinetic energy store remains constant because the speed is constant B1\n- **Section B:** Identifies that the chemical energy store of the battery continues to decrease to overcome resistive forces, with energy transferred to thermal energy stores B1\n- **Section C:** Identifies that the kinetic energy store of the scooter decreases to zero as the speed decreases B1\n- **Section C:** Identifies that kinetic energy is transferred mechanically (by friction in the brakes) to the thermal energy stores of the brakes and surroundings B1","marks":6,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"energy_stores","label":"Track energy stores","steps":[{"type":"text","order":1,"title":"Explain section A","content":"In section A, the line rises, so the scooter’s speed increases. Its **kinetic energy store** therefore increases. This earns the first mark for A.\n\nThe battery’s **chemical energy store decreases**. Energy is transferred **electrically** from the battery and then **mechanically** to the scooter’s kinetic energy store. Some energy is dissipated to **thermal energy stores** because of friction and air resistance. This earns the second mark for A.","highlights":[{"text":"all three sections (A, B, and C)","location":"specification"}]},{"type":"text","order":2,"title":"Explain section B","content":"In section B, the line is horizontal, so the scooter’s speed is constant. Its **kinetic energy store remains constant**. This earns the first mark for B.\n\nThe battery’s **chemical energy store still decreases**: energy is needed to overcome resistive forces, including friction and air resistance. This energy is transferred to **thermal energy stores** of the scooter and surroundings. This earns the second mark for B.","highlights":[{"text":"all three sections (A, B, and C)","location":"specification"}]},{"type":"text","order":3,"title":"Explain section C","content":"In section C, the line slopes down to zero, so the scooter slows down and stops. Its **kinetic energy store decreases to zero**. This earns the first mark for C.\n\nKinetic energy is transferred **mechanically** by friction in the brakes to the **thermal energy stores** of the brakes and the surroundings. This earns the second mark for C.","highlights":[{"text":"all three sections (A, B, and C)","location":"specification"}]}]}],"generatedAt":"2026-07-22T09:14:49.025Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"3fe50a52-0ee1-4c52-ac90-d61a2822d9d8","revisionId":"1c95ca5d-34ca-41e7-ad38-55fbe45700c5","questionNumber":null,"questionType":"LA","specification":"A piece of space debris of mass \$ 25\\text{ g} \$ is travelling through the thermosphere.","difficulty":4,"difficultyBand":"medium","totalMarks":3,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"4cea6359-5428-4368-84db-57174d2e2eca","label":null,"content":"Calculate the kinetic energy of the piece of debris when its speed is \$ 80\\text{ m s}^{-1} \$.","markscheme":"- Converts mass to kg: $m = 0.025\\text{ kg}$ B1\n- Recalls or uses the formula for kinetic energy: $E_k = \\frac{1}{2}mv^2$ with $v = 80$ and their $m$ M1\n- Calculates the kinetic energy as $80\\text{ J}$ A1","marks":3,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"kinetic_energy","label":"Calculate kinetic energy","steps":[{"type":"text","order":1,"title":"Convert the mass","content":"The formula needs mass in kilograms, so convert grams to kilograms by dividing by $1000$:\n\n$$m=0.025\\text{ kg}$$\n\nThis unit conversion earns the **B1** mark.","highlights":[{"text":"mass \$ 25\\text{ g} \$","location":"specification"}]},{"type":"hyper_latex","block":{"node

Energy stores, transfers and conservation

Question 4

Energy stores, transfers and conservation Questions

Energy stores, transfers and conservation

Question 4

Energy stores, transfers and conservation Questions