Olympiad: forces, floating and machines ★★★

Tests: 2 of 11 right · Exam: 2 of 4 right · Kind: ★★★ · Understood: 6 of 15 · Run: 2026-10-18, commit f3c23ea72

Lesson 42 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 · ★★★ · wrong ✗

Jaz, from Yorkshire: "This box weighs a ton, I'm literally dying, our kid." What does he really mean?

1. The box is as heavy as a whole lorry — no support
2. The box is very heavy for him — ✓ the right answer · no support
3. The box weighs exactly 1,000 kilograms — ← Mova's choice · score 5
4. The box is light, he is just bored — no support

Why: It took the question to ask what it is done to. It chose option 3 with score 5, the only option with support. Its support: lesson 42, line 17: «"This weighs a ton" is hyperbole: a ton is 1,000 kilograms, about as much as a small car, and no school bag or box a child can carry weighs that.», 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 thing acted on «1,000 kilograms» (+2). The right option, 2, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 2 · ★★★ · wrong ✗

Jaz rigs up pulleys so that 4 lengths of rope hold the box. What changes for him?

1. He no longer needs to pull at all, it lifts itself — ← Mova's choice · no support
2. He pulls four times as hard but only a quarter as far — no support
3. He pulls just as hard, but the rope is shorter — no support
4. He pulls a quarter as hard but four times as far — ✓ 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 · ★★★ · right ✓

A cartoon astronaut on the Moon drops a hammer and a feather, and the feather drifts down slowly. Fix it.

1. With no air, they land together — ← Mova's choice · ✓ the right answer · score 8
2. The feather should land first — score 7
3. The hammer should float upwards — no support
4. Nothing, that's how it would go — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 8, against 7 for the next best. Its support: lesson 1, line 17: «In 1971 the astronaut David Scott dropped a hammer and a falcon feather on the Moon, and they landed together.», reached through a sentence linked to the one the question matched. What matched: the same action «land» (+4); the same doer «hammer» (+3); the same property (+1). · the question and its options parsed, with trees and pragmatics

Test 4 · ★★★ · wrong ✗

Lily, from Glasgow: "Ma wee brother's 20 kilos an' sits 3 metres oot on the seesaw. Ah'm 30. Where dae Ah sit?" ("wee" means little, "oot" means out.)

1. 3 metres from the middle — ← Mova's choice · no support
2. 4 and a half metres out — no support
3. 2 metres from the middle — ✓ the right answer · no support
4. 1 metre from the middle — 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 5 · ★★★ · wrong ✗

Gran: "Back in my day we lifted the shed with a long pole and a brick under it." Where should the brick go for the easiest lift?

1. Close to your hands, far from the shed — no support
2. Close to the shed, with your hands far out — ✓ the right answer · no support
3. Under the shed itself, not the pole — ← Mova's choice · score 11
4. In the very middle of the long pole — no support

Why: It took the question to ask where. It chose option 3 with score 11, the only option with support. Its support: lesson 39, line 10: «The whole night sky seems to turn round one point because the Earth spins; the North Star sits almost above the North Pole and hardly moves, and sailors used i…», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+7); the same place «north pole» (+5). Against it: 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 6 · ★★★ · wrong ✗

"Big gear's got 24 teeth, no wait, 36, and the little one's got 12. Big one turns once, how many turns for the little un?"

1. 36 — ← Mova's choice · no support
2. 2 — no support
3. 12 — no support
4. 3 — ✓ 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 7 · ★★★ · wrong ✗

Kai reckons a heavy kid on a swing goes back and forth faster than a light kid on the same swing. Right?

1. Yes, but only on long swings — ← Mova's choice · no support
2. No, the heavy kid is slower — no support
3. Yes, heavy kids swing faster — no support
4. No, they take the same time — ✓ 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 8 · ★★★ · wrong ✗

"lowkey my egg floated in the tap water, mum says it's fine to eat, no cap?" ("no cap" means no lie.) What's sensible?

1. Floating means it is hard-boiled already — no support
2. All eggs float in tap water — ← Mova's choice · score 9
3. A floating egg may be rotten, so don't eat it — ✓ the right answer · score 3
4. Floating means the egg is extra fresh — no support

Why: It took the question to ask which statement is true. It chose option 2 with score 9, against 3 for the next best. Its support: lesson 11, line 15: «An egg sinks in tap water but floats when lots of salt is stirred in, and a rotten egg floats even in fresh water because gas has built up inside.», reached through the option's own match among the sentences about the question's things. What matched: the same action «float» (+4); the same doer «rotten egg» (+3); the same place «fresh water» (+2). The right option, 3, scored 3. · the question and its options parsed, with trees and pragmatics

Test 9 · ★★★ · wrong ✗

Put these in order from easiest to hardest pull: the same sack held by 1 length of rope, by 2 lengths, by 4 lengths.

1. 1 length, 2 lengths, 4 lengths — ← Mova's choice · no support
2. 4 lengths, 2 lengths, 1 length — ✓ the right answer · no support
3. 2 lengths, 4 lengths, 1 length — no support
4. All three take the same pull — 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 10 · ★★★ · wrong ✗

Four claims: ice floats on water, a steel ship floats, a clay boat floats, a clay ball floats. Which claim is false?

1. A steel ship floats — score 9
2. Ice floats on water — ← Mova's choice · score 11
3. A clay ball floats — ✓ the right answer · no support
4. A clay boat floats — no support

Why: It took the question to ask who or what does it. It chose option 2 with score 11, against 9 for the next best. Its support: lesson 13, line 5: «Thick, very cold ice can carry a heavy lorry across a frozen lake in the far north, but ice on ponds at home can look solid and be far too thin, so never walk…», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+5); the same doer «thick cold ice» (+3); the same place «water» (+3). The right option, 3, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 11 · ★★★ · right ✓

Ellie weighs 30 kilograms on scales in a lift, and for a moment they show 33. What is the lift doing?

1. Just starting to go up — ← Mova's choice · ✓ the right answer · score 9
2. Standing still at a floor — no support
3. Moving down at a steady speed — score 2
4. Starting to go down — score 9

Why: It took the question to ask what is done. It chose option 1 with score 9, tied with another option at 9 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 2, line 14: «In a lift that starts to go up, scales show more for a moment; in one that starts to go down, they show less.», 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 «start» (+3); the same doer «lift» (+2). · the question and its options parsed, with trees and pragmatics

Exam question 1 · formal language · right ✓

Determine the direction of rotation of the sixth gear in a row of meshing gears, the first of which rotates clockwise.

1. Anticlockwise — ← Mova's choice · ✓ the right answer · no support
2. It alternates in direction — no support
3. Clockwise — no support
4. It remains stationary — 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 · wrong ✗

Ascertain the distance from the pivot at which a 40-kilogram child must sit to balance a 20-kilogram child seated 2 metres from it.

1. 4 metres — ← Mova's choice · no support
2. 2 metres — no support
3. 1 metre — ✓ the right answer · no support
4. Half a metre — 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 ✗

Select the statement which correctly describes a body of mass 1 kilogram carried to the Moon.

1. Its mass and its weight both fall to about one sixth — ← Mova's choice · no support
2. Its mass falls to zero and its weight is unchanged — no support
3. Both its mass and its weight remain wholly unchanged — no support
4. Its mass is unchanged and its weight is about one sixth — ✓ 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 · right ✓

Identify the outcome when a vessel passes from fresh water into sea water.

1. It floats slightly higher — ← Mova's choice · ✓ the right answer · no support
2. Its depth is wholly unaltered — no support
3. It floats slightly lower — no support
4. It sinks to the bottom — 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

This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/physics/42-olympiad-forces-floating-and-machines/