# Topic Questions: 25b understand that this equation applies only to small spherical objects moving at low speeds with laminar flow (or in the absence of turbulent flow) and that viscosity is temperature dependent — WPH11 Materials > 52 WPH11 Materials topic questions (113 marks) on 25b understand that this equation applies only to… — 22 papers, 2019–2026. Open the exact question in the… - Canonical HTML: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-1-wph11/materials/25b-understand-that-this-equation-applies-only-to-small-spherical-objects-moving-at/ - Markdown mirror: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-1-wph11/materials/25b-understand-that-this-equation-applies-only-to-small-spherical-objects-moving-at/index.md --- Edexcel IAL · Physics · WPH11 · Materials 52 WPH11 Materials topic questions are tagged to this syllabus point across 22 papers (2019–2026). Only the parts whose knowledge graph matches this syllabus statement are counted, and the table shows which parts of each question are involved. - 52 topic questions - 22 papers - 113 tagged marks - 18.4% of topic questions - 15.8% of topic marks - 2019–2026 - Syllabus 2018–current - [All WPH11 Materials topic questions](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-1-wph11/materials/) - [All paper codes](https://www.examsci.com/topics/) Core finding **This Materials syllabus point appears in 22 WPH11 papers across 2019–2026, contributing 52 topic questions and 113 marks.** The most recent appearance is WPH11/01 January 2026. That equals 18.4% of the 282 topic questions and 15.8% of the 713 marks tagged to Materials. Only parts tagged to this subtopic are counted, so a four-part question can contribute one item and one part's marks. The table lists every matching question, its tagged parts and marks, with a link back to the paper page. Sessions are newest first, so the statement can be traced back through the full paper history. ## Topic questions by session Newest sessions first. Parts and marks count only the parts tagged to this subtopic; “x of y parts” shows how much of the question is tagged elsewhere. Select the paper cell to open the matching question on the paper page, or use **Go to Practice Hub** to answer that exact question in the Interactive Practice Hub. | Paper | Question | Type | Parts | Marks | Difficulty | Practice | | --- | --- | --- | --- | --- | --- | --- | | [**WPH11/01** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2026-january-wph11-01/#q-15) | **Q15** Stokes' Law and Viscosity - Edexcel IAL Physics Unit 1 Jan 2026 Q15 | FRQ | 1 of 3 parts ((a)) | 2 of 10 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=f7bbb48f-3899-4c6f-b09f-fa826d328a68&question_id=49f3d9f9-f5f4-48ab-b90d-70e843930492&source_detail=WPH11%2F01+January+2026) | | [**WPH11/02** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2026-january-wph11-02/#q-7) | **Q7** Upthrust and Viscous Drag - Edexcel IAL Physics Jan 2026 Q7 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=a80f5748-5313-4f69-a34e-e8d485474f9c&question_id=df150270-0349-46b5-b6aa-be7f4cefc9a2&source_detail=WPH11%2F02+January+2026) | | [**WPH11/02** January 2026 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2026-january-wph11-02/#q-14) | **Q14** Viscous Drag and Stokes' Law - Edexcel IAL Physics Jan 2026 Q14 | FRQ | 1 of 3 parts ((a)) | 2 of 7 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=a80f5748-5313-4f69-a34e-e8d485474f9c&question_id=d0c7f710-356a-4040-8467-683440b089ad&source_detail=WPH11%2F02+January+2026) | | [**WPH11/01** October 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2025-october-wph11-01/#q-4) | **Q4** Terminal Velocity in Oil - Edexcel IAL Physics Oct 2025 Q4 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=a2261024-0662-4c0a-8d29-27981b3c8593&question_id=5bded02c-474a-485f-9885-e55007ea6fd3&source_detail=WPH11%2F01+October+2025) | | [**WPH11/01** October 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2025-october-wph11-01/#q-17) | **Q17** Seawater Lifting Bag and Air Bubble - Edexcel IAL Physics Oct 2025 Q17 | FRQ | 1 of 3 parts ((b)(ii)) | 2 of 11 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=a2261024-0662-4c0a-8d29-27981b3c8593&question_id=538926f5-3bab-4199-a301-ccfbf967c91b&source_detail=WPH11%2F01+October+2025) | | [**WPH11/02** October 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2025-october-wph11-02/#q-13) | **Q13** Applicability of Stokes' Law on Sphere - Edexcel IAL Physics Oct 2025 Q13 | FRQ | 1 of 2 parts ((a)) | 1 of 6 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=206d9659-8eb1-4877-a884-b687de9cdf96&question_id=6a15299f-9fce-4f8b-bbf2-e3b36519e5df&source_detail=WPH11%2F02+October+2025) | | [**WPH11/01** June 2025 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2025-june-wph11-01/#q-16) | **Q16** Determining Viscosity of Vegetable Oil - Edexcel IAL Physics Jun 2025 Q16 | FRQ | 1 of 3 parts ((c)) | 3 of 7 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=2a1cdf33-a9db-4ce2-b66a-788f175d980c&question_id=57562f25-cb17-4a56-87df-6d1e5a279f44&source_detail=WPH11%2F01+June+2025) | | [**WPH11/01** October 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2024-october-wph11-01/#q-19) | **Q19** Stokes' Law and Dive Velocity Analysis - Edexcel IAL Physics Oct 2024 Q19 | FRQ | 1 of 4 parts ((a)(i)) | 2 of 12 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=abf33b21-e4d9-4ff8-ad87-235e71deb7e0&question_id=eb8f13e4-f6ae-4bc1-8ae0-cca6117cb4aa&source_detail=WPH11%2F01+October+2024) | | [**WPH11/01** June 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2024-june-wph11-01/#q-3) | **Q3** Conditions for Stokes' Law - Edexcel IAL Physics Jun 2024 Q3 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=60c883e1-3934-457c-b1ff-60cf87441771&question_id=8bc11956-93fa-4bce-ad92-972bd7f53bec&source_detail=WPH11%2F01+June+2024) | | [**WPH11/01** June 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2024-june-wph11-01/#q-14) | **Q14** Terminal Velocity and Stokes' Law of Sand in Water - Edexcel IAL Physics Jun 2024 Q14 | FRQ | 2 of 3 parts ((b), (c)) | 5 of 6 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=60c883e1-3934-457c-b1ff-60cf87441771&question_id=96d0e96d-899f-4baa-99fc-e0a9bf6f5c12&source_detail=WPH11%2F01+June+2024) | | [**WPH11/01** January 2024 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2024-january-wph11-01/#q-15) | **Q15** Viscosity of Liquid and Stokes' Law - Edexcel IAL Physics Jan 2024 Q15 | FRQ | 1 of 3 parts ((a)) | 2 of 10 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=230a3ed8-7572-4cb0-87e1-cead15943437&question_id=cf9f69e1-b6d5-4a86-9657-ca09d813eb72&source_detail=WPH11%2F01+January+2024) | | [**WPH11/01** October 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2023-october-wph11-01/#q-18) | **Q18** Ball-Bearing Falling through Liquid - Edexcel IAL Physics Oct 2023 Q18 | FRQ | 2 of 4 parts ((a), (b)(iii)) | 6 of 13 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=15e3f88f-24f6-422e-8f4a-6de82da3ed98&question_id=31db3fae-712c-4fa5-b99a-442989a2b9fe&source_detail=WPH11%2F01+October+2023) | | [**WPH11/01** June 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2023-june-wph11-01/#q-9) | **Q9** Terminal Velocity and Temperature - Edexcel IAL Physics Unit 1 Summer 2023 Q9 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=dc6d3961-d2d0-430e-815a-816bfd3cb268&question_id=fbc7f21a-ccb4-4181-9ae2-f49acf487ff7&source_detail=WPH11%2F01+June+2023) | | [**WPH11/01** June 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2023-june-wph11-01/#q-16) | **Q16** Air Bubble Viscous Drag and Stokes' Law - Edexcel IAL Physics Unit 1 Summer 2023 Q16 | FRQ | 1 of 3 parts ((a)) | 1 of 7 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=dc6d3961-d2d0-430e-815a-816bfd3cb268&question_id=e0eafce0-a244-43bd-9064-b107427b4d80&source_detail=WPH11%2F01+June+2023) | | [**WPH11/01** January 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2023-january-wph11-01/#q-12) | **Q12** Viscosity of a Liquid - Edexcel IAL Physics Jan 2023 Q12 | FRQ | 1 of 2 parts ((b)) | 2 of 6 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9b8108c7-40af-4a33-b373-0ba0dae27340&question_id=4cc815b4-d15a-4c51-a566-88d7b358cdb2&source_detail=WPH11%2F01+January+2023) | | [**WPH11/01** January 2023 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2023-january-wph11-01/#q-18) | **Q18** Terminal Velocity and Buoyancy - Edexcel IAL Physics Jan 2023 Q18 | FRQ | 2 of 4 parts ((a)(ii), (a)(iii)) | 4 of 12 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9b8108c7-40af-4a33-b373-0ba0dae27340&question_id=25bd158a-f8cd-47a5-bf37-33553ae74b2a&source_detail=WPH11%2F01+January+2023) | | [**WPH11/01** October 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2022-october-wph11-01/#q-3) | **Q3** Stokes' Law Application Conditions - Edexcel IAL Physics Oct 2022 Q3 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e613f67e-77fc-4141-8190-504991cfb0ac&question_id=13198e05-bbc3-4e4e-89b0-fc7ee67a8b8c&source_detail=WPH11%2F01+October+2022) | | [**WPH11/01** October 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2022-october-wph11-01/#q-14) | **Q14** Helium Balloon Forces and Upwards Motion - Edexcel IAL Physics Oct 2022 Q14 | FRQ | 1 of 2 parts ((b)) | 6 of 10 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e613f67e-77fc-4141-8190-504991cfb0ac&question_id=919cb8a2-1adf-4e41-aed3-391386a368ad&source_detail=WPH11%2F01+October+2022) | | [**WPH11/01** October 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2022-october-wph11-01/#q-17) | **Q17** Sinking Foraminifera and Stokes' Law - Edexcel IAL Physics Oct 2022 Q17 | FRQ | 3 parts ((a)(i), (a)(ii), (b)) | 9 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e613f67e-77fc-4141-8190-504991cfb0ac&question_id=2b2d6757-8d71-4b14-aae9-3d3d06b3b4bf&source_detail=WPH11%2F01+October+2022) | | [**WPH11/01** June 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2022-june-wph11-01/#q-2) | **Q2** Forces on falling sphere - Edexcel IAL Physics Jun 2022 Q2 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=a4a954db-f07e-437a-8405-65316f754d19&question_id=87969290-c08e-4cb9-9031-4e6f364b46ed&source_detail=WPH11%2F01+June+2022) | | [**WPH11/01** June 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2022-june-wph11-01/#q-19) | **Q19** Viscometer and Stokes' Law - Edexcel IAL Physics Jun 2022 Q19 | FRQ | 4 of 5 parts ((a), (b)(ii), (b)(iii), (c)) | 10 of 14 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=a4a954db-f07e-437a-8405-65316f754d19&question_id=e31fe914-8262-459e-9c0a-10cc647afdf9&source_detail=WPH11%2F01+June+2022) | | [**WPH11/01** January 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2022-january-wph11-01/#q-6) | **Q6** Terminal Velocity Viscosity Gradient - Edexcel IAL Physics Jan 2022 Q6 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1b234f87-a29d-4049-b582-537e5e9160a9&question_id=27e55c61-6001-4369-be55-a823233e5152&source_detail=WPH11%2F01+January+2022) | | [**WPH11/01** January 2022 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2022-january-wph11-01/#q-17) | **Q17** Sphere Motion in Viscous Liquid - Edexcel IAL Physics Jan 2022 Q17 | FRQ | 2 of 4 parts ((a), (c)) | 6 of 11 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1b234f87-a29d-4049-b582-537e5e9160a9&question_id=3840c711-ded4-46b3-af15-312aea93f9eb&source_detail=WPH11%2F01+January+2022) | | [**WPH11/01** October 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2021-october-wph11-01/#q-9) | **Q9** Stokes' Law Conditions - Edexcel IAL Physics Oct 2021 Q9 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=c6a436cd-ce2e-4b48-9819-5ec3a7ae39c6&question_id=af421264-64db-4883-beaa-cebac0022678&source_detail=WPH11%2F01+October+2021) | | [**WPH11/01** October 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2021-october-wph11-01/#q-17) | **Q17** Water Droplets in Oil - Edexcel IAL Physics Oct 2021 Q17 | FRQ | 2 of 5 parts ((a)(i), (b)(iii)) | 5 of 11 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=c6a436cd-ce2e-4b48-9819-5ec3a7ae39c6&question_id=dff54fee-0655-4739-a838-ded194cfb249&source_detail=WPH11%2F01+October+2021) | | [**WPH11/01** June 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2021-june-wph11-01/#q-18) | **Q18** Viscosity of a Liquid and Stokes' Law - Edexcel IAL Physics Jun 2021 Q18 | FRQ | 3 of 5 parts ((b), (c)(i), (c)(iii)) | 10 of 15 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=5059932b-1c99-4e4c-90f2-0dc7111b867a&question_id=e041a5ae-0f57-4a5c-b020-ea504b2988df&source_detail=WPH11%2F01+June+2021) | | [**WPH11/01** January 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2021-january-wph11-01/#q-7) | **Q7** Terminal Velocity Practical - Edexcel IAL Physics Jan 2021 Q7 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=731e4d52-84b1-40ad-99c4-b89586f8f9db&question_id=1ca942a2-06b1-4e91-882e-35b37d4b840b&source_detail=WPH11%2F01+January+2021) | | [**WPH11/01** January 2021 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2021-january-wph11-01/#q-18) | **Q18** Viscosity of Oil and Stokes' Law - Edexcel IAL Physics Jan 2021 Q18 | FRQ | 3 of 4 parts ((a), (c)(i), (c)(ii)) | 8 of 11 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=731e4d52-84b1-40ad-99c4-b89586f8f9db&question_id=50596576-7aa8-4e16-bc3d-435b5a0f5694&source_detail=WPH11%2F01+January+2021) | | [**WPH11/01** October 2020 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2020-october-wph11-01/#q-15) | **Q15** Viscosity of Oil Core Practical - Edexcel IAL Physics Oct 2020 Q15 | FRQ | 3 of 6 parts ((a)(i), (b)(iii), (b)(iv)) | 4 of 8 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=de7f3e55-de2d-40f1-9868-c21f740ee82c&question_id=3089741c-358b-4f01-968b-5656338267c0&source_detail=WPH11%2F01+October+2020) | | [**WPH11/01** January 2020 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2020-january-wph11-01/#q-10) | **Q10** Falling Object in Liquid Graph Analysis - Edexcel IAL Physics Jan 2020 Q10 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a116037-6139-44bc-8f9d-116738b54706&question_id=590d5b12-f76d-4fdf-bc06-57b5e84f9045&source_detail=WPH11%2F01+January+2020) | | [**WPH11/01** January 2020 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2020-january-wph11-01/#q-12) | **Q12** Stokes' Law Applicability Assessment - Edexcel IAL Physics Jan 2020 Q12 | FRQ | 1 of 2 parts ((a)) | 1 of 6 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=1a116037-6139-44bc-8f9d-116738b54706&question_id=2d8bdbc6-3a3b-45da-93b9-e24167a1b6f5&source_detail=WPH11%2F01+January+2020) | | [**WPH11/01** October 2019 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2019-october-wph11-01/#q-14) | **Q14** Boat Stability and Ballast Tanks - Edexcel IAL Physics Oct 2019 Q14 | FRQ | 1 of 4 parts ((b)(ii)) | 2 of 11 on the paper | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=5f3717ec-f750-4f16-a54f-f18cdccc3eb0&question_id=e6a0427f-8300-4abc-ba74-7b0784aef77d&source_detail=WPH11%2F01+October+2019) | | [**WPH11/01** October 2019 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2019-october-wph11-01/#q-15) | **Q15** Core Practical: Viscosity of Washing Up Liquid - Edexcel IAL Physics Oct 2019 Q15 | FRQ | 2 of 4 parts ((a)(ii), (b)(ii)) | 8 of 14 on the paper | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=5f3717ec-f750-4f16-a54f-f18cdccc3eb0&question_id=c67442fc-b751-42a8-a674-aa73d085040b&source_detail=WPH11%2F01+October+2019) | | [**WPH11/01** June 2019 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2019-june-wph11-01/#q-5) | **Q5** Settling of Sand Particles - Edexcel IAL Physics Jun 2019 Q5 | MCQ | MCQ · 1 part | 1 | Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=9c0ae983-58e3-4d98-b727-ddb00ea25c86&question_id=4b48b2d0-088d-4f87-a265-4f74907ae669&source_detail=WPH11%2F01+June+2019) | | [**WPH11/01** January 2019 · Edexcel IAL](https://www.examsci.com/past-papers/edexcel-ial/physics/physics-unit-1-wph11/2019-january-wph11-01/#q-3) | **Q3** Stokes' Law Application - Edexcel IAL Physics Jan 2019 Q3 | MCQ | MCQ · 1 part | 1 | Easy | [Go to Practice Hub](https://www.examsci.com/practice?set_id=34ce4699-61aa-4a3f-abf1-62330761fb43&question_id=2d61d10d-56c1-445f-939c-3112b82b9d6f&source_detail=WPH11%2F01+January+2019) | ## Related topic questions in Materials - [23 be able to use the equation density $\rho=\frac{m}{V}$](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-1-wph11/materials/23-be-able-to-use-the-equation-density-rho-frac-m-v/) — 37 question items · 22 papers — 129 marks · 2019–2026 - [24 understand how to use the relationship upthrust = weight of fluid displaced](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-1-wph11/materials/24-understand-how-to-use-the-relationship-upthrust-weight-of-fluid-displaced/) — 59 question items · 23 papers — 197 marks · 2019–2026 - [25a be able to use the equation for viscous drag (Stokes' Law), $F = 6\pi\eta r v$.](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-1-wph11/materials/25a-be-able-to-use-the-equation-for-viscous-drag-stokes-law-f-6-pi-eta-r-v/) — 60 question items · 23 papers — 158 marks · 2019–2026 - [26 CORE PRACTICAL 2: Use a falling-ball method to determine the viscosity of a liquid](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-1-wph11/materials/26-core-practical-2-use-a-falling-ball-method-to-determine-the-viscosity-of-a-liquid/) — 14 question items · 8 papers — 33 marks · 2019–2025 - [27 be able to use the Hooke's law equation, $\Delta F=k\Delta x$, where k is the stiffness of the object](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-1-wph11/materials/27-be-able-to-use-the-hooke-s-law-equation-delta-f-k-delta-x-where-k-is-the-stiffness/) — 35 question items · 22 papers — 85 marks · 2019–2026 - [28 understand how to use the relationships • (tensile or compressive) stress = force/cross-sectional area • (tensile or compressive) strain = change in length/original length Young modulus = stress/strain.](https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-1-wph11/materials/28-understand-how-to-use-the-relationships-tensile-or-compressive-stress-force-cross/) — 62 question items · 23 papers — 165 marks · 2019–2026 ## Topic question rules and edge cases **How many topic questions cover this syllabus point?** 35 question stems cover this subtopic across 22 papers, but only 52 tagged parts and 113 marks belong to it. Other parts of the same questions are assessed under different statements and are excluded from this page. **Which papers include this subtopic?** The table lists every matching session from 2019–2026. Each row links to the question anchor on the paper page, where the full paper context and practice entry point are available. **Why can one question appear under several subtopics?** The parts of one question can assess different syllabus statements. Each part is counted under its own subtopics, so the same question stem can appear on several subtopic pages while each page lists only the parts and marks tagged to that statement. **Can I practise these questions with AI marking?** Yes. Open a paper from the table and use the Interactive Practice Hub entry point. The page itself is static HTML so search engines and retrieval agents can read the full question list without executing JavaScript. --- Full page with native tables, bar charts and Practice Hub links: https://www.examsci.com/topics/edexcel-ial/physics/physics-unit-1-wph11/materials/25b-understand-that-this-equation-applies-only-to-small-spherical-objects-moving-at/