he power equation. Substituting both values correctly earns the method mark."},{"type":"hyper_latex","block":{"nodes":[{"text":"Now evaluate the product."},{"latex":"E=\\htmlData{anchor=energy}{2.925\\times10^{12}\\text{ J}}"}],"highlights":[{"color":"green","style":"box","anchor":"energy"}]},"order":3,"title":"Calculate the energy","description":"This is already in standard form because the coefficient 2.925 is between 1 and 10. This earns the final accuracy mark."}]}],"generatedAt":"2026-07-22T09:30:11.067Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]},{"id":"5a695be7-aa6f-4a79-947a-405fed2e9731","label":"c","content":"Nuclear power stations do not generate electricity every day of the year due to scheduled maintenance. A specific nuclear power station operated for $88\\%$ of a year (where $1\\text{ year} = 365\\text{ days}$). Calculate the number of days during that year that the power station generated electricity.","markscheme":"- Sets up the calculation for $88\\%$ of $365$ days: $\\frac{88}{100} \\times 365$ M1\n- Obtains the final answer of $321.2\\text{ days}$ A1","marks":2,"order":2,"markingRubric":null,"explanation":{"methods":[{"id":"percentage_of_year","label":"Find a percentage","steps":[{"type":"text","order":0,"title":"Identify the whole year","content":"The whole year is $365\\text{ days}$. We need $88\\%$ of this total, because the station operated for $88\\%$ of the year.","highlights":[{"text":"operated for $88\\%$ of a year (where $1\\text{ year} = 365\\text{ days}$)","location":"specification"}]},{"type":"hyper_latex","block":{"nodes":[{"latex":"\\htmlData{anchor=calculation}{\\frac{88}{100}\\times365}"},{"latex":"\\htmlData{anchor=answer}{=321.2\\text{ days}}"}],"highlights":[{"color":"green","style":"box","anchor":"answer"}],"connections":[{"to":"answer","from":"calculation","color":"sky","label":"calculate"}]},"order":1,"title":"Calculate the percentage","description":"Write the percentage as a fraction out of 100, then multiply by 365 days. This setup earns M1; 321.2 days earns A1."}]}],"generatedAt":"2026-07-22T09:32:20.727Z","modelVersion":"gpt-5.6-terra+diagrams-1","explanationVersion":"v3"},"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null},{"id":"9caccab0-af4f-43af-9043-2064ded93994","revisionId":"91f86457-8aec-498c-9787-5beb4aab437f","questionNumber":null,"questionType":"LA","specification":"An autonomous delivery drone cruises at a constant velocity of \$12\\text{ m/s}\$. At this velocity, the drone's kinetic energy is \$1.8\\text{ kJ}\$.","difficulty":4,"difficultyBand":"medium","totalMarks":3,"sourceTitle":null,"calculatorUse":null,"parts":[{"id":"72401abf-56d7-4350-826e-4ae8a1da6cce","label":null,"content":"Calculate the mass of the drone in kilograms.\n\nState the equation used and show your working.","markscheme":"- States the correct formula: $E_k = \\frac{1}{2}mv^2$ (or any correct rearrangement) B1\n- Converts energy to Joules ($1800\\text{ J}$) and substitutes the values: $1800 = \\frac{1}{2} \\times m \\times 12^2$ M1\n- Rearranges and solves to find $m = 25\\text{ kg}$ A1","marks":3,"order":0,"markingRubric":null,"explanation":{"methods":[{"id":"rearrange_kinetic_energy","label":"Rearrange the kinetic-energy equation","steps":[{"type":"hyper_latex","block":{"nodes":[{"latex":"E_k=\\frac{1}{2}mv^2"},{"text":"Here, Ek is kinetic energy, m is mass and v is velocity."}]},"order":1,"title":"State the equation","description":"Use the kinetic-energy equation. This earns B1."},{"type":"hyper_latex","block":{"nodes":[{"latex":"E_k=1.8\\text{ kJ}=1800\\text{ J}"},{"latex":"1800=\\frac{1}{2}\\times m\\times 12^2"}]},"order":2,"title":"Convert and substitute","description":"The equation requires energy in joules. Convert 1.8 kJ to 1800 J before substituting. This conversion and substitution earn the M1 mark."},{"type":"hyper_latex","block":{"nodes":[{"latex":"1800=\\frac{1}{2}m\\times144"},{"latex":"3600=144m"},{"latex":"m=\\frac{3600}{144}=25\\text

Energy changes in a system, and the ways energy is stored before and after such changes

Question 28

Energy changes in a system, and the ways energy is stored before and after such changes Questions

Energy changes in a system, and the ways energy is stored before and after such changes

Question 28

Energy changes in a system, and the ways energy is stored before and after such changes Questions