中文（繁體）
中文（简体）
English
S1 Science: Heat and Temperature – Conduction, Convection, Radiation and the Vacuum Flask (Paper 2: intermediate)
← Back to the Secondary Science chapter index
Tutor Prep Guide · heat against temperature, conduction convection and radiation, specific heat capacity calculations, and how a vacuum flask keeps drinks hot
S1 Science: Heat and Temperature – Conduction, Convection, Radiation and the Vacuum Flask (Paper 2: intermediate)
Paper two joins specific heat calculations to flask design, working out energy and time.
Direct answers Remember one line: get the energy first, then divide by power for the time.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 20 |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1 |
| Chapter | Chapter: S1 Science: Heat and Temperature – Conduction, Convection, Radiation and the Vacuum Flask |
| Level | heat against temperature, conduction convection and radiation, specific heat capacity calculations, and how a vacuum flask keeps drinks hot |
02 Questions (10 items)
- FoundationWhich two heat paths does the vacuum layer of a flask block?
- FoundationWhat does the silvered inner wall of a flask do?
- FoundationA black mug and a white mug hold the same hot water. Which cools faster?
- IntermediateWhy does double glazing insulate better than single glazing?
- IntermediateHow much energy raises 0.3 kg of water by 25 C?
- IntermediateHow much heat do 3 kg of water take to go from 15 C to 95 C?
- ChallengeBoiling 2 kg of water from 20 C to 100 C with a 1500 W kettle (100 percent efficient) takes how long?
- ChallengeSame kettle at 80 percent efficiency: how long?
- ChallengeWhy is a cork or foam stopper used on a flask?
- Error redoA student writes that convection can happen in a vacuum. What is wrong?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | Conduction and convection. | A vacuum has almost no particles, so both conduction and convection are cut off. |
| 2 | It reflects radiation back inside, cutting radiative loss. | A shiny surface reflects radiation and emits less. |
| 3 | The black one, since dark surfaces absorb and emit radiation better. | A dark surface is both a good absorber and a good emitter. |
| 4 | The trapped air layer is a poor conductor, so conduction drops. | Still air conducts badly, so it acts as an insulating layer. |
| 5 | 31 500 J. | 0.3 times 4200 times 25 gives 31 500 J. |
| 6 | 1 008 000 J, that is 1008 kJ. | 3 times 4200 times 80 gives 1 008 000 J. |
| 7 | 672 000 J divided by 1500 W is about 448 seconds, some 7.5 minutes. | 2 times 4200 times 80 gives 672 000 J, and dividing by 1500 gives 448 seconds. |
| 8 | It needs 840 000 J of input, about 560 seconds. | Divide the useful energy by 0.8 to get 840 000 J, then by 1500 W for 560 seconds. |
| 9 | These are poor conductors, so less heat leaves by conduction through the neck, and air convection is blocked too. | The neck is the biggest loss point, and a stopper cuts both conduction and convection there. |
| 10 | Convection needs a fluid to rise and sink; a vacuum has none, so only radiation remains. | In a vacuum only radiation can carry heat. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
Then try paper three, mixing hot and cold water and comparing specific heat.Tutor Registration →
Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.