---
title: Keeping warm and keeping cool: insulation and sweat — how Mova does on the tests · Physics
description: Lesson 25 of the physics course of Mova's primary school: 3 of 11 tests right, exam 0 of 4, every question with the options, the student's choice, the right answer and why it chose.
---

<!-- md -->
[Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/school-run/physics/25-keeping-warm-and-keeping-cool/)

<!-- crumbs -->
[home](https://md.mova.elamur.ai/free/en/) / [at school](https://md.mova.elamur.ai/free/en/school-run/) / [Physics](https://md.mova.elamur.ai/free/en/school-run/physics/) / 25

# Keeping warm and keeping cool: insulation and sweat

<!-- .vintro -->
**Tests:** 3 of 11 right · **Exam:** 0 of 4 right · **Kind:** ★★★ · **Understood:** 9 of 15 · **Run:** 2026-10-18, commit `f3c23ea72`

<!-- .vabout -->
Lesson 25 of the physics course of Mova's primary school, as Mova's small model took its tests: it had read this lesson and the ones before it and learned from their exercises. Each test shows the options in the order the student saw them, its choice, the right answer, the score of every option and why it chose. The lesson itself, sentence by sentence with trees and pragmatics: [the lesson in the corpora](https://md.mova.elamur.ai/free/en/corpora/school/physics/25-keeping-warm-and-keeping-cool/).

<!-- .vabout -->
Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: [the lesson's questions in the corpora](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/).

<!-- div qa ok -->

### Test 1 · ★★★ · right ✓ {#t1}

<!-- .q -->
Mum says "put a jumper on, it'll warm you up!" What is the more exact truth?

- **1.** The jumper soaks heat from the air into you — score 4
- **2.** The jumper only works when it is new — no support
- **3.** The jumper makes heat from the wool — score 6
- **4.** The jumper keeps in heat your body makes; it makes none itself — **← Mova's choice** · **✓ the right answer** · score 10

<!-- .why -->
**Why:** It took the question to ask which statement is true. It chose option 4 with score 10, against 6 for the next best. Its support: lesson 25, line 1: «A woolly jumper does not make any heat; your body makes it, and the jumper traps still air between its fibres, which passes heat very badly, so the heat stays…», reached through a sentence linked to the one the question matched. What matched: the same action «make» (+4); the same doer «body» (+3); the same thing acted on «heat» (+3). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/t1/)

<!-- /div -->

<!-- div qa no -->

### Test 2 · ★★★ · wrong ✗ {#t2}

<!-- .q -->
A friend wants to keep his ice lolly frozen on a hot walk. Which would help most?

- **1.** Wave it about in the warm air — **← Mova's choice** · no support
- **2.** Hold it tightly in his bare hand — no support
- **3.** Wrap it in a thick woolly scarf — **✓ the right answer** · no support
- **4.** Put it in a black plastic bag in the Sun — no support

<!-- .why -->
**Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/t2/)

<!-- /div -->

<!-- div qa no -->

### Test 3 · ★★★ · wrong ✗ {#t3}

<!-- .q -->
What would happen to a polar bear if its fur got soaked and flat?

- **1.** Nothing at all would change — **← Mova's choice** · no support
- **2.** It would lose heat faster, because the trapped air was gone — **✓ the right answer** · no support
- **3.** It would warm up faster — no support
- **4.** It would turn white all over — no support

<!-- .why -->
**Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/t3/)

<!-- /div -->

<!-- div qa no -->

### Test 4 · ★★★ · wrong ✗ {#t4}

<!-- .q -->
A dog is panting hard in the back of a hot car with the windows shut. What should you do?

- **1.** Wait about an hour and then check whether the dog has cooled down — **← Mova's choice** · score 6
- **2.** Leave it, dogs like warm cars — score 4
- **3.** Get an adult to help at once, because it is an emergency — **✓ the right answer** · no support
- **4.** Give it a jumper to cover up — score 5

<!-- .why -->
**Why:** It took the question to ask what is done. It chose option 1 with score 6, against 5 for the next best. Its support: lesson 25, line 13: «Dogs hardly sweat, so they cool down by panting, which dries their wet tongue and mouth.», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+4); the same action «cool down» (+3). Against it: a different doer (counts against) (-1). The right option, 3, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/t4/)

<!-- /div -->

<!-- div qa ok -->

### Test 5 · ★★★ · right ✓ {#t5}

<!-- .q -->
why'd I get goosebumps getting out the pool when it's bloody 28 degrees out?

- **1.** The pool water is secretly frozen — no support
- **2.** Hot days make you colder inside — no support
- **3.** Water drying off your skin is pulling heat away — **← Mova's choice** · **✓ the right answer** · score 3
- **4.** Your skin forgets how to be warm after swimming — no support

<!-- .why -->
**Why:** It took the question to ask why something happens (its cause). It chose option 3 with score 3, the only option with support. Its support: lesson 25, line 12: «You feel cold getting out of a pool, even on a warm day, because the water on your skin evaporates and carries heat away, and wind makes it faster.», reached through the same lesson line as the sentence the question matched. What matched: the same doer «water» (+2); the same thing acted on «heat» (+2). Against it: a different action (counts against) (-1). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/t5/)

<!-- /div -->

<!-- div qa no -->

### Test 6 · ★★★ · wrong ✗ {#t6}

<!-- .q -->
In a cartoon a snowman melts faster because someone puts a coat on him "to keep him cosy". What is wrong?

- **1.** The coat would make him grow — **← Mova's choice** · score 5
- **2.** A coat would slow the melting, not speed it up — **✓ the right answer** · no support
- **3.** Nothing, coats always warm up whatever is inside them — no support
- **4.** Coats make snow turn into steam — score 5

<!-- .why -->
**Why:** It took the question to ask which statement is true. It chose option 1 with score 5, tied with another option at 5 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 25, line 7: «Insulation slows heat flow in both directions, so a coat wrapped round a snowman makes it last longer.», reached through the option's own match among the sentences about the question's things. What matched: the same action «make» (+3); the same doer «coat» (+2). The right option, 2, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/t6/)

<!-- /div -->

<!-- div qa no -->

### Test 7 · ★★★ · wrong ✗ {#t7}

<!-- .q -->
A flask of hot tea and a flask of iced juice sit side by side all day. What is clever about the flask?

- **1.** It simply slows heat in either direction, not knowing hot from cold — **✓ the right answer** · score 2
- **2.** It only works on one of them — no support
- **3.** It knows which drink is hot and which is cold — no support
- **4.** It turns the juice warm and the tea cold — **← Mova's choice** · score 4

<!-- .why -->
**Why:** It took the question to ask which statement is true. It chose option 4 with score 4, against 2 for the next best. Its support: lesson 25, line 2: «Insulation slows heat moving either way, so the same coat that keeps you warm would keep a snowman cold, and the same flask keeps tea hot and juice cold all da…», reached through the option's own match among the sentences about the question's things. What matched: the same thing acted on «tea» (+3); the same doer «same flask» (+2). Against it: a different action (counts against) (-1). The right option, 1, scored 2. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/t7/)

<!-- /div -->

<!-- div qa ok -->

### Test 8 · ★★★ · right ✓ {#t8}

<!-- .q -->
Why might a desert fox have huge ears while an Arctic fox has tiny ones?

- **1.** Arctic foxes have no use for ears — score 5
- **2.** Desert foxes need to hear camels — no support
- **3.** Big ears lose heat in the heat, small ears save heat in the cold — **← Mova's choice** · **✓ the right answer** · score 8
- **4.** Big ears grow only in sand — score 6

<!-- .why -->
**Why:** It took the question to ask why something happens (its cause). It chose option 3 with score 8, against 6 for the next best. Its support: lesson 25, line 17: «Desert foxes have big ears that help them lose heat, while Arctic foxes have small ears that keep heat in.», reached through the same lesson line as the sentence the question matched. What matched: the same action «lose» (+4); the same doer «ears» (+2); the same thing acted on «heat» (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/t8/)

<!-- /div -->

<!-- div qa no -->

### Test 9 · ★★★ · wrong ✗ {#t9}

<!-- .q -->
Two identical houses are heated in winter, but one has fluffy loft insulation and double windows. Which needs less fuel?

- **1.** The house without insulation — **← Mova's choice** · score 3
- **2.** Both need exactly the same — no support
- **3.** Neither needs any fuel at all — score 3
- **4.** The insulated house — **✓ the right answer** · no support

<!-- .why -->
**Why:** It took the question to ask who or what does it. It chose option 1 with score 3, tied with another option at 3 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 25, line 10: «Thick walls, fluffy loft insulation and double windows slow heat leaking out of a house, so it needs much less fuel to keep warm.», reached through the option's own match among the sentences about the question's things. What matched: the same action «need» (+2); the same thing acted on «less fuel» (+2). Against it: a different doer (counts against) (-1). The right option, 4, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/t9/)

<!-- /div -->

<!-- div qa no -->

### Test 10 · ★★★ · wrong ✗ {#t10}

<!-- .q -->
A runner on a humid, still day overheats far more than on a dry, breezy day at the same temperature. Why?

- **1.** Breezes make the Sun's rays much weaker, so they heat her less — **← Mova's choice** · no support
- **2.** Sweat dries badly in humid, still air, so it cools her less — **✓ the right answer** · no support
- **3.** Humid air is always hotter — no support
- **4.** Dry air makes runners slower — no support

<!-- .why -->
**Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/t10/)

<!-- /div -->

<!-- div qa no -->

### Test 11 · ★★★ · wrong ✗ {#t11}

<!-- .q -->
You put a wet cloth round a bottle of water and leave it in the breeze. What happens to the water?

- **1.** It freezes solid in minutes — **← Mova's choice** · score 5
- **2.** It gets cooler as the cloth dries — **✓ the right answer** · no support
- **3.** It gets warmer as the cloth dries — no support
- **4.** Nothing changes at all — no support

<!-- .why -->
**Why:** It took the question to ask which statement is true. It chose option 1 with score 5, the only option with support. Its support: lesson 24, line 11: «Fresh water freezes at 0 degrees, and water grows as it turns to ice, which is why frozen pipes can burst.», reached through the option's own match among the sentences about the question's things. What matched: the same action «freeze» (+3); the same doer «fresh water» (+2). The right option, 2, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/t11/)

<!-- /div -->

<!-- div qa no -->

### Exam question 1 · formal language · wrong ✗ {#e1}

<!-- .q -->
Identify the principal means by which a woollen garment maintains the warmth of the wearer.

- **1.** The reflection of the cold of the air away from the body of the wearer — **← Mova's choice** · no support
- **2.** The generation of heat by the fibres — no support
- **3.** The retention of still air, which is a poor conductor of heat — **✓ the right answer** · no support
- **4.** The absorption of heat from the surroundings — no support

<!-- .why -->
**Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/e1/)

<!-- /div -->

<!-- div qa no -->

### Exam question 2 · formal language · wrong ✗ {#e2}

<!-- .q -->
Which of the following statements most accurately characterises the cooling effect of perspiration?

- **1.** Perspiration reflects the rays of the Sun — **← Mova's choice** · no support
- **2.** Perspiration is intrinsically of low temperature when it is produced — no support
- **3.** Perspiration seals heat within the skin — no support
- **4.** Evaporation of moisture from the skin removes heat from the body — **✓ the right answer** · no support

<!-- .why -->
**Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/e2/)

<!-- /div -->

<!-- div qa no -->

### Exam question 3 · formal language · wrong ✗ {#e3}

<!-- .q -->
It is given that an animal is to be left in a closed vehicle exposed to the Sun. Ascertain the hazard thereby presented.

- **1.** The interior cools progressively — **← Mova's choice** · no support
- **2.** No hazard of any description is presented to the animal within — no support
- **3.** The interior remains at the external temperature — no support
- **4.** The interior temperature rises rapidly to a dangerous level — **✓ the right answer** · no support

<!-- .why -->
**Why:** No option found support in what it remembers, so it guessed: it took the first option shown. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/e3/)

<!-- /div -->

<!-- div qa no -->

### Exam question 4 · formal language · wrong ✗ {#e4}

<!-- .q -->
State the reason for which a vacuum flask preserves the temperature of its contents in either direction.

- **1.** It distinguishes hot contents from cold — no support
- **2.** It contains a heating element — no support
- **3.** The near absence of air between its walls impedes the passage of heat — **✓ the right answer** · no support
- **4.** It generates cold within its walls — **← Mova's choice** · score 6

<!-- .why -->
**Why:** It took the question to ask which statement is true. It chose option 4 with score 6, the only option with support. Its support: lesson 25, line 9: «A flask has two walls with almost no air between them, so heat can hardly cross, and shiny walls bounce heat rays back.», reached through the remembered sentence the question matched. What matched: the same circumstance (+5); the same doer «flask» (+1). The right option, 3, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/25-keeping-warm-and-keeping-cool/e4/)

<!-- /div -->

<!-- pn -->
- ← previous: [24. Melting, freezing and boiling](https://md.mova.elamur.ai/free/en/school-run/physics/24-melting-freezing-and-boiling/)
- next →: [26. Static electricity: balloons, hair and sparks](https://md.mova.elamur.ai/free/en/school-run/physics/26-static-electricity-balloons-hair-and-sparks/)
- ↑ back to [Physics](https://md.mova.elamur.ai/free/en/school-run/physics/)