The Moon, the planets and the pull that holds them

Tests: 5 of 11 right · Exam: 3 of 4 right · Kind: ★ · Understood: 10 of 15 · Run: 2026-10-18, commit f3c23ea72

Lesson 2 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 ✗

Is there no gravity in space, like my cousin says?

1. Right, gravity only works on the ground — ← Mova's choice · score 4
2. Right, gravity stops where the air stops — no support
3. There is; astronauts float because they fall together — ✓ the right answer · no support
4. There is, but only near the Sun — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 4, the only option with support. Its support: lesson 2, line 9: «Up at the space station, gravity is still almost as strong as on the ground.», reached through the option's own match among the sentences about the question's things. What matched: the same doer «gravity» (+2); the same circumstance (+2). The right option, 3, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 2 · ★ · right ✓

In a film the hero lets go of a sling and the stone curves round the corner. What would really happen?

1. It flies off in a straight line — ← Mova's choice · ✓ the right answer · score 3
2. It flies straight back to the hero — no support
3. It drops straight down to the ground at once — no support
4. It keeps curving round in a circle — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 3, the only option with support. Its support: lesson 2, line 8: «Let go of a ball swung on a string and it flies off in a straight line, not in a curve.», reached through a sentence linked to the one the question matched. What matched: the same action «fly off» (+2); the same place «straight line» (+2). Against it: a different doer (counts against) (-1). · the question and its options parsed, with trees and pragmatics

Test 3 · ★ · right ✓

What would happen to the Moon if the Earth's gravity switched off?

1. It would fly away in a straight line — ← Mova's choice · ✓ the right answer · score 8
2. It would fall onto the Earth — score 2
3. It would stop dead in space — no support
4. It would spin faster and faster round us — no support

Why: It took the question to ask what happens next. It chose option 1 with score 8, against 2 for the next best. Its support: lesson 2, line 7: «If the Earth's gravity switched off, the Moon would fly away in a straight line.», reached through what followed the sentence the question matched. What matched: the same action «fly away» (+4); the same place «straight line» (+4); the same property (+2). Against it: a different doer (counts against) (-2). · the question and its options parsed, with trees and pragmatics

Test 4 · ★ · wrong ✗

lol on the moon ur not lighter u just feel lighter. right?

1. Yes, only your mass gets smaller — ← Mova's choice · no support
2. No, you weigh nothing at all there — no support
3. No, you really weigh less, but your mass stays — ✓ the right answer · no support
4. Yes, your weight stays exactly the same — 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 ✗

You stand on scales in a lift that suddenly starts going down. What do the scales show for a moment?

1. Exactly the same — ← Mova's choice · score 10
2. More than usual — score 10
3. Zero, all the time — score 8
4. Less than usual — ✓ the right answer · score 10

Why: It took the question to ask what it is done to. It chose option 1 with score 10, tied with another option at 10 (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 remembered sentence the question matched. What matched: the same action «show» (+4); the same doer «scales» (+4); the same property (+2). The right option, 4, scored 10. · the question and its options parsed, with trees and pragmatics

Test 6 · ★ · wrong ✗

A lift's cable snaps. Why would the people inside feel like floating for a moment?

1. They and the lift fall together — ✓ the right answer · no support
2. Gravity stops working inside a lift — score 1
3. The lift goes up first, then down — ← Mova's choice · score 6
4. Air rushes in and holds them up high — no support

Why: It took the question to ask why something happens (its cause). It chose option 3 with score 6, against 1 for the next best. 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: the same action «go up» (+3); the same doer «lift» (+3). The right option, 1, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 7 · ★ · right ✓

A satellite slows down a lot. What happens to it?

1. It floats still, staying where it is — no support
2. It drops into the air and burns up — ← Mova's choice · ✓ the right answer · score 3
3. It falls gently down like a feather — no support
4. It flies off towards the Moon instead — no support

Why: It took the question to ask which statement is true. It chose option 2 with score 3, the only option with support. Its support: lesson 2, line 16: «Satellites that tell your phone where you are fall round the Earth like little moons, high above the air, with no engine needed; if one slows down too much, it…», reached through the same lesson line as the sentence the question matched. What matched: the same action «drop» (+2); the same place «air» (+2). Against it: a different doer (counts against) (-1). · the question and its options parsed, with trees and pragmatics

Test 8 · ★ · right ✓

Why would you hardly be able to lift your feet on Jupiter?

1. Jupiter pulls more than twice as hard as Earth — ← Mova's choice · ✓ the right answer · no support
2. Jupiter's thick air holds your feet down like glue — no support
3. Jupiter spins your feet down — no support
4. Your mass doubles on Jupiter — 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 9 · ★ · wrong ✗

crap, i swung the bucket too slow at the top. what happens?

1. The bucket gets lighter — ← Mova's choice · no support
2. The water freezes in place — no support
3. The water pours on your head — ✓ the right answer · no support
4. Nothing, water never falls out — 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 · ★ · right ✓

Why do roller coaster riders get strapped in, though the car is going fast?

1. In case the car is not fast enough at the top — ← Mova's choice · ✓ the right answer · score 3
2. Because the track pushes them out — no support
3. To stop them floating up into the sky at the top — no support
4. Because gravity is stronger in loops — no support

Why: It took the question to ask why something happens (its cause). It chose option 1 with score 3, the only option with support. Its support: lesson 2, line 19: «A roller coaster car stays on the track upside down in a loop because it is going fast enough that the track has to keep pushing it round.», reached through the option's own match among the sentences about the question's things. What matched: the same doer «car» (+2); the same property (+1). · the question and its options parsed, with trees and pragmatics

Test 11 · ★ · wrong ✗

What makes a shooting star glow?

1. The air in front of it gets squashed and very hot — ✓ the right answer · score 4
2. It is burning like a real star — ← Mova's choice · score 14
3. It reflects light from the Moon — score 8
4. It has a tiny battery inside it — score 10

Why: It took the question to ask who or what does it. It chose option 2 with score 14, against 10 for the next best. Its support: lesson 2, line 17: «A shooting star is not a star: it is a bit of space rock, often no bigger than a grain of sand, glowing as it rushes into the air, because the air in front of…», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+6); the same action «glow» (+4); the same doer «star» (+4). The right option, 1, scored 4. · 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 condition of astronauts aboard an orbiting space station?

1. They are in continual free fall about the Earth together with the station — ← Mova's choice · ✓ the right answer · score 2
2. They are sustained by the pressure of the cabin air — no support
3. They are beyond the reach of terrestrial gravitation — no support
4. They are repelled by the gravitation of the Sun — no support

Why: It took the question to ask who or what does it. It chose option 1 with score 2, the only option with support. Its support: lesson 2, line 10: «Astronauts float because they and the station are falling round the Earth together, so nothing presses on the floor.», reached through the option's own match among the sentences about the question's things. What matched: the same circumstance (+2); the same property (+1). Against it: a different doer (counts against) (-1). · the question and its options parsed, with trees and pragmatics

Exam question 2 · formal language · wrong ✗

Identify the principal reason for which the Earth does not descend into the Sun.

1. The Sun exerts a repulsive force upon the Earth — ← Mova's choice · no support
2. The gravitation of the Sun does not extend so far — no support
3. Its lateral velocity continually carries it past the Sun — ✓ the right answer · no support
4. The intervening space impedes all motion — 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 · right ✓

It is given that a person is transported to the surface of the Moon. Determine which quantity remains unaltered.

1. The mass of the person — ← Mova's choice · ✓ the right answer · no support
2. The reading of a spring balance — no support
3. The weight of the person — no support
4. The height attainable in a jump — 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

Exam question 4 · formal language · right ✓

Ascertain the trajectory of a ball swung upon a cord in a circle at the instant at which the cord is released.

1. A straight line — ← Mova's choice · ✓ the right answer · score 3
2. A continuation of the circle — no support
3. A vertical descent to the ground — no support
4. A return towards the hand — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 3, the only option with support. Its support: lesson 2, line 8: «Let go of a ball swung on a string and it flies off in a straight line, not in a curve.», reached through the same lesson line as the sentence the question matched. What matched: the same place «straight line» (+2); the same property (+1). · the question and its options parsed, with trees and pragmatics

This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/physics/2-the-moon-the-planets-and-the-pull/