Energy: what makes things happen

Tests: 4 of 11 right · Exam: 1 of 4 right · Kind: plain · Understood: 9 of 15 · Run: 2026-10-18, commit f3c23ea72

Lesson 31 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.

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 · right ✓

ugh my teacher says energy never gets used up. but my phone battery literally died??

1. The energy is still in the battery, just hiding — no support
2. The phone ate the energy and it's gone — score 3
3. The energy changed into other forms, mostly heat and light — ← Mova's choice · ✓ the right answer · score 7
4. Your teacher is wrong, energy gets destroyed — no support

Why: It took the question to ask which statement is true. It chose option 3 with score 7, against 3 for the next best. Its support: lesson 31, line 4: «Energy is never used up, it only changes form: when a bouncing ball gets lower each bounce, the missing energy has turned into a little heat and sound.», reached through a sentence linked to the one the question matched. What matched: the same action «change» (+4); the same doer «energy» (+3). · the question and its options parsed, with trees and pragmatics

Test 2 · wrong ✗

Liam says his porridge is basically old sunshine. Is he right?

1. No, food has no energy at all — ← Mova's choice · no support
2. No, porridge energy comes from the cooker — no support
3. Yes, but only if he eats it outside — no support
4. Yes, the oats grew by catching sunlight — ✓ 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 3 · wrong ✗

If the Sun went out, what would happen to wind power on Earth?

1. It would be the only kind of power left that still works — score 2
2. It would fail, because the Sun drives the wind — ✓ the right answer · score 2
3. It would get stronger without sunshine — ← Mova's choice · score 4
4. Nothing, the wind does not need the Sun — no support

Why: It took the question to ask what happens next. It chose option 3 with score 4, against 2 for the next best. Its support: lesson 20, line 4: «A low morning Sun stretches your shadow long across the playground, while the high Sun at midday shrinks it to a puddle at your feet.», reached through what followed the sentence the question matched. What matched: the same doer «high sun» (+4). The right option, 2, scored 2. · the question and its options parsed, with trees and pragmatics

Test 4 · right ✓

In a cartoon, a ball bounces forever just as high each time. What's wrong?

1. A real ball loses some energy as heat and sound each bounce — ← Mova's choice · ✓ the right answer · score 5
2. Balls should stop after exactly one bounce — score 4
3. Nothing, balls bounce forever — score 5
4. Balls should bounce higher each time — score 5

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 31, line 4: «Energy is never used up, it only changes form: when a bouncing ball gets lower each bounce, the missing energy has turned into a little heat and sound.», reached through the option's own match among the sentences about the question's things. What matched: the same thing acted on «bounce» (+3); the same doer «bouncing ball» (+2). · the question and its options parsed, with trees and pragmatics

Test 5 · right ✓

Gran sits still in her chair all day. Is her body using energy?

1. Only when she is asleep — no support
2. No, energy is only used up when you move about — score 3
3. Yes, it turns food into heat to keep her warm — ← Mova's choice · ✓ the right answer · score 5
4. No, old people do not use energy — score 3

Why: It took the question to ask which statement is true. It chose option 3 with score 5, against 3 for the next best. Its support: lesson 31, line 4: «Energy is never used up, it only changes form: when a bouncing ball gets lower each bounce, the missing energy has turned into a little heat and sound.», reached through the option's own match among the sentences about the question's things. What matched: the same action «turn» (+3); the same place «little heat» (+2). · the question and its options parsed, with trees and pragmatics

Test 6 · right ✓

A wind-up mouse has stopped. How can you give it more energy?

1. Wind its spring up again — ← Mova's choice · ✓ the right answer · no support
2. Shake it hard — no support
3. Put it in the sunshine — no support
4. Leave it to rest overnight — 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 7 · wrong ✗

what's the point of a solar panel at night then, it's useless innit

1. Panels work the same day and night — score 1
2. It stores the dark for later — no support
3. It makes even more at night from moonlight — ← Mova's choice · score 3
4. At night it makes no electricity, which is why homes also use mains power or batteries — ✓ the right answer · score 3

Why: It took the question to ask which statement is true. It chose option 3 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 31, line 13: «A solar panel turns light straight into electricity; it makes less on a cloudy day and none at night.», reached through the option's own match among the sentences about the question's things. What matched: the same action «make» (+3). The right option, 4, scored 3. · the question and its options parsed, with trees and pragmatics

Test 8 · wrong ✗

Coal, oil and gas are sometimes called "stored sunshine". Why?

1. They are only dug up in sunny countries — ← Mova's choice · no support
2. They formed from living things that caught sunlight long ago — ✓ the right answer · no support
3. They glow faintly yellow in the dark — no support
4. They were melted together by the Sun — 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 · wrong ✗

Mum says the water behind the dam is "stored energy". What does she mean?

1. Water up high can fall and spin a turbine — ✓ the right answer · no support
2. The water is electric already — no support
3. The water is hot inside — ← Mova's choice · score 4
4. The water is full of tiny batteries, like a phone — no support

Why: It took the question to ask what it is done to. It chose option 3 with score 4, the only option with support. Its support: lesson 11, line 3: «Something floats if it is lighter than the same size of water: wood floats, a stone sinks, and a hollow steel ship floats because it is mostly air inside.», reached through the option's own match among the sentences about the question's things. What matched: the same doer «water» (+2); the same property (+1); the same light verb (be, have, do, get, go) (+1). The right option, 1, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 10 · wrong ✗

Why do you need more food on a cold day outside than on a warm day at home?

1. Cold air makes the food inside you smaller — ← Mova's choice · score 6
2. Your body uses more energy to keep warm — ✓ the right answer · score 6
3. Your tummy grows a lot bigger when it is cold — no support
4. You lose food out through your skin in the cold — no support

Why: It took the question to ask why something happens (its cause). 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 14, line 2: «It presses from every side at once, up, down and sideways, on you, on the table and on the top of your juice.», reached through the option's own match among the sentences about the question's things. What matched: the same circumstance (+3); the same doer «air» (+2); a different action (counts against) (+1). The right option, 2, scored 6. · the question and its options parsed, with trees and pragmatics

Test 11 · wrong ✗

A bow and arrow and a wind-up toy store energy in the same kind of way. How?

1. Both store it as heat — score 6
2. Both store it in the air around them until it is needed — ← Mova's choice · score 8
3. Both store it in a battery — score 6
4. Both store it by bending or coiling something springy — ✓ the right answer · score 6

Why: It took the question to ask which statement is true. It chose option 2 with score 8, against 6 for the next best. Its support: lesson 31, line 16: «A wind-up toy stores energy in a coiled spring, like a bent bow or a stretched rubber band.», reached through the option's own match among the sentences about the question's things. What matched: the same action «store» (+3); the same thing acted on «energy» (+3); the same circumstance (+2). The right option, 4, scored 6. · the question and its options parsed, with trees and pragmatics

Exam question 1 · formal language · wrong ✗

Identify the original source of the energy contained within the greater part of human food.

1. The motion of the oceans — ← Mova's choice · no support
2. Heat derived from the cooker — no support
3. Sunlight captured by plants — ✓ the right answer · no support
4. Minerals dissolved in the soil — 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 2 · formal language · right ✓

Which of the following statements most accurately characterises the conservation of energy?

1. Energy may change its form, but its total quantity remains constant — ← Mova's choice · ✓ the right answer · score 12
2. Energy is lost entirely when a device ceases operation — no support
3. Energy is created anew whenever an object moves — no support
4. Energy is consumed and destroyed by every machine — score 1

Why: It took the question to ask who or what does it. It chose option 1 with score 12, against 1 for the next best. Its support: lesson 31, line 15: «Energy can change form, but the total amount stays the same; it is never used up.», 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 «change» (+3); the same doer «energy» (+3); the same thing acted on «form» (+2). · the question and its options parsed, with trees and pragmatics

Exam question 3 · formal language · wrong ✗

Ascertain the reason for which a bouncing ball attains a diminished height upon each successive rebound.

1. The air within the ball is extracted by the floor — ← Mova's choice · no support
2. A portion of its energy is converted into heat and sound upon impact — ✓ the right answer · no support
3. The gravitational force increases after each impact — no support
4. The mass of the ball increases upon contact with the floor — 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 consistent with the established facts concerning the origin of wind energy.

1. The gravitational attraction of the Moon — ← Mova's choice · no support
2. The motion of trees and vegetation — no support
3. Unequal heating of the atmosphere by the Sun — ✓ the right answer · no support
4. The rotation of the turbine blades themselves — 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

This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/physics/31-energy-what-makes-things-happen/