Thinking it through — forces, heat, light and energy

Tests: 3 of 13 right · Exam: 1 of 4 right · Kind: ★★★ · Understood: 12 of 17 · Run: 2026-10-18, commit f3c23ea72

Lesson 60 of the world 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.

Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: the lesson's questions in the corpora.

Test 1 · ★★★ · wrong ✗

A cook leaves a metal spoon and a plastic spoon in a pot of hot soup for five minutes. Which handle is safe to hold?

1. The metal one, because metal stays cool while the soup is hot — ← Mova's choice · score 5
2. Both, because heat cannot move up a spoon — no support
3. Neither, because plastic is the better conductor — no support
4. The plastic one, because plastic is a poor conductor of heat — ✓ the right answer · no support

Why: It took the question to ask who or what does it. It chose option 1 with score 5, the only option with support. Its support: lesson 18, line 5: «For example, a metal spoon left in hot tea soon has a hot handle, but a wooden spoon does not, because metal conducts heat and wood insulates.», 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 doer «metal» (+3). Against it: a different action (counts against) (-2). The right option, 4, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 2 · ★★★ · wrong ✗

A shadow stick is put in the ground. During the day its shadow first shortens, then grows again. Why?

1. The stick grows and shrinks with the heat — no support
2. The Sun climbs higher until midday, then sinks lower — ✓ the right answer · score 5
3. Clouds make shadows change their length — score 3
4. The Earth moves closer to the Sun at noon — ← Mova's choice · score 11

Why: It took the question to ask why something happens (its cause). It chose option 4 with score 11, against 5 for the next best. Its support: lesson 60, line 4: «Because light travels in straight lines, a shadow points away from the Sun. In the morning and evening the Sun is low, so shadows are long; at midday the Sun i…», reached through the cause of the sentence the question matched. What matched: the same action «move» (+5); the same circumstance (+4); a different doer (counts against) (+2). The right option, 2, scored 5. · the question and its options parsed, with trees and pragmatics

Test 3 · ★★★ · wrong ✗

You count 6 seconds between a lightning flash and its thunder, and later only 3 seconds. What has happened?

1. The storm has come closer — ✓ the right answer · no support
2. The thunder has become faster — no support
3. The storm has moved further away — ← Mova's choice · score 5
4. The lightning has become slower — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 5, the only option with support. Its support: lesson 40, line 5: «Light travels about a million times faster than sound, so we see lightning almost at once but hear the thunder later; sound takes about 3 seconds to go one kil…», reached through the same lesson line as the sentence the question matched. What matched: the same doer «storm» (+4); the same property (+1). The right option, 1, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 4 · ★★★ · wrong ✗

Two children try to move a boulder with the same bar. One holds it near the pivot, the other at the far end. Who needs less force?

1. Neither, since bars do not help — no support
2. The one holding near the pivot — no support
3. The one holding the far end — ✓ the right answer · no support
4. They need exactly the same force — ← Mova's choice · score 9

Why: It took the question to ask who or what does it. It chose option 4 with score 9, the only option with support. Its support: lesson 52, line 8: «The further from the pivot you push, the less force you need to lift a load.», reached through the remembered sentence the question matched. What matched: the same action «need» (+4); the same thing acted on «less force» (+4); 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

Test 5 · ★★★ · wrong ✗

Why do polar bears' thick fur and fat help them survive the Arctic?

1. They reflect the cold back into the air before it reaches the skin — ← Mova's choice · score -1
2. They make heat from the snow that sticks to the bears' coats — score -1
3. They let the cold flow quickly into the body to toughen it — no support
4. They trap heat in and slow down its escape into the cold — ✓ the right answer · no support

Why: It took the question to ask why something happens (its cause). It chose option 1 with score -1, tied with another option at -1 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 57, line 11: «Reducing waste helps most, because the waste is never made.», reached through the cause of the sentence the question matched. What matched: the same action «make» (+5). Against it: one says «not», the other does not (counts against) (-6). The right option, 4, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 6 · ★★★ · wrong ✗

An evening walker in the countryside sees his long shadow stretching ahead of him. Which way is he walking?

1. He could be walking any way at all — no support
2. East, away from the setting Sun — ✓ the right answer · no support
3. West, towards the setting Sun — no support
4. North, towards the Pole Star — ← Mova's choice · score 3

Why: It took the question to ask a circumstance (with what, when, how). It chose option 4 with score 3, the only option with support. Its support: lesson 10, line 5: «An astronomer cannot travel to the stars, so he reasons from what he sees: shadows, shapes, timings and the rules of light and gravity.», reached through the same lesson line as the sentence the question matched. What matched: it fills the role the question asks for (+3); the same circumstance (+2). Against it: a different action (counts against) (-1); a different doer (counts against) (-1). The right option, 2, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 7 · ★★★ · right ✓

Which is true about a lever that lets you lift a heavy load with a small push?

1. It creates extra energy from nothing — no support
2. Your end has to move a longer distance — ← Mova's choice · ✓ the right answer · score 5
3. The load becomes truly lighter — no support
4. Your end moves a shorter distance — score 5

Why: It took the question to ask which statement is true. It chose option 2 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 60, line 8: «A lever with a long arm on your side lets a small force lift a heavy load, but your end moves further.», reached through a sentence linked to the one the question matched. What matched: the same action «move» (+3); the same doer «end» (+2). · the question and its options parsed, with trees and pragmatics

Test 8 · ★★★ · wrong ✗

On a hot summer day, why do people in sunny countries often paint houses white?

1. White paint makes cold air — ← Mova's choice · no support
2. White reflects sunlight, so the houses stay cooler — ✓ the right answer · no support
3. White houses are heavier and thicker — no support
4. White walls absorb more heat to store it — no support

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

Test 9 · ★★★ · right ✓

A thermos keeps tea hot for hours. What is the main idea of how it works?

1. It uses electricity from the tea — no support
2. It keeps the cold from flowing in like water — no support
3. It stops heat flowing out from the hot tea to the colder air — ← Mova's choice · ✓ the right answer · score 1
4. It makes new heat inside the flask — no support

Why: It took the question to ask what it is done to. It chose option 3 with score 1, the only option with support. Its support: lesson 60, line 2: «Heat moves from hotter things to colder things. Metals are good conductors of heat, so heat travels quickly along a metal spoon in hot tea up to your fingers;…», reached through the option's own match among the sentences about the question's things. What matched: the same doer «heat» (+2); the same place «hot tea» (+1). Against it: a different action (counts against) (-2). · the question and its options parsed, with trees and pragmatics

Test 10 · ★★★ · wrong ✗

why's the metal spoon in my tea hot but the wooden one not

1. The tea just likes metal more, it sticks to it harder — ← Mova's choice · no support
2. Metal makes its own heat whenever it gets dunked in tea — no support
3. Metal conducts heat well, wood conducts it poorly — ✓ the right answer · no support
4. Wood is colder inside, it's like full of tiny ice bits — no support

Why: Nothing it remembers matched the question, so it guessed: it took the first option shown. · the question and its options parsed, with trees and pragmatics

Test 11 · ★★★ · wrong ✗

evening, sun going down, which way's my shadow pointing

1. North — ← Mova's choice · no support
2. West — no support
3. South — no support
4. East — ✓ the right answer · no support

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

Test 12 · ★★★ · wrong ✗

my brother says a coat makes heat to keep you warm. true?

1. Yes, coats make their own heat — ← Mova's choice · score 4
2. Yes, wool burns slowly — no support
3. No, coats only keep rain off — no support
4. No, air trapped in it slows the heat leaving your body — ✓ the right answer · score 2

Why: It took the question to ask which statement is true. It chose option 1 with score 4, against 2 for the next best. Its support: lesson 40, line 3: «Burning food also makes heat, so you get hot. Sweat cools you because water takes heat from the skin when it evaporates. When you are cold, the opposite happen…», reached through the remembered sentence the question matched. What matched: the same action «make» (+3); the same thing acted on «heat» (+1). The right option, 4, scored 2. · the question and its options parsed, with trees and pragmatics

Test 13 · ★★★ · right ✓

a classmate says cold flows from the ice into your hand. right?

1. Yes, cold moves into warm things, that's why your hand hurts — no support
2. No, nothing flows at all — no support
3. No, heat flows from your warm hand into the ice — ← Mova's choice · ✓ the right answer · score 5
4. Yes, ice gives out cold — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 5, the only option with support. Its support: lesson 60, line 6: «Heat flows from hotter things to colder things.», reached through the remembered sentence the question matched. What matched: the same action «flow» (+3); the same doer «heat» (+2). · the question and its options parsed, with trees and pragmatics

Exam question 1 · formal language · right ✓

Which of the following statements most accurately characterises the direction of the flow of heat?

1. Heat flows from the hotter body to the colder body — ← Mova's choice · ✓ the right answer · score 6
2. Heat flows only between bodies of equal temperature — score 6
3. Heat flows exclusively through metals — score 6
4. Heat flows from the colder body to the hotter body — score 6

Why: It took the question to ask who or what does it. It chose option 1 with score 6, tied with another option at 6 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 60, line 6: «Heat flows from hotter things to colder things.», reached through the remembered sentence the question matched. What matched: the same action «flow» (+4); it fills the role the question asks for (+2). · the question and its options parsed, with trees and pragmatics

Exam question 2 · formal language · wrong ✗

It is given that the Sun stands in the east at morning. Determine the direction in which shadows shall then point.

1. Towards the east — ← Mova's choice · no support
2. Directly downwards — no support
3. Towards the north — no support
4. Towards the west — ✓ the right answer · no support

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

Exam question 3 · formal language · wrong ✗

It is given that lightning is observed and the thunder is heard six seconds subsequently. Ascertain the approximate distance of the storm.

1. About half a kilometre — ← Mova's choice · no support
2. About eighteen kilometres — no support
3. About six kilometres — no support
4. About two kilometres — ✓ the right answer · no support

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

Exam question 4 · formal language · wrong ✗

Select the response that is consistent with the established facts concerning the output of energy of any machine.

1. A well-built machine gives out more energy than it receives — no support
2. No machine gives out more energy than is put into it — ✓ the right answer · no support
3. A lever gives out twice the energy put into it — no support
4. A machine creates energy whenever it is in motion — ← Mova's choice · score 2

Why: It took the question to ask which statement is true. It chose option 4 with score 2, the only option with support. Its support: lesson 52, line 15: «A machine that saves force always makes you move further; it never saves work for free.», reached through the option's own match among the sentences about the question's things. What matched: the same doer «machine» (+2); the same action «make» (+1). Against it: a different thing acted on (counts against) (-1). The right option, 2, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/world/60-reasoning-energy-technology/