Balance: the centre of gravity
Tests: 4 of 11 right · Exam: 2 of 4 right · Kind: ★ · Understood: 2 of 15 · Run: 2026-10-18, commit f3c23ea72
Lesson 8 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 ✗
My cousin says you balance only with your feet. right?
- 1. No, you balance with your arms only — ← Mova's choice · no support
- 2. Yes, that is why shoes have soles — no support
- 3. Yes, feet do all the balancing — no support
- 4. No, your eyes and inner ears help a lot — ✓ 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 2 · ★ · right ✓
Try it: back against the wall, touch your toes. What happens?
- 1. You touch them easily — score 1
- 2. You fall backwards through the wall — no support
- 3. You tip forward or give up — ← Mova's choice · ✓ the right answer · score 3
- 4. You float up a little — no support
Why: It took the question to ask what happens next. It chose option 3 with score 3, against 1 for the next best. Its support: lesson 8, line 11: «When you lean forward, your hips go back to keep your balance, so with your back against a wall you cannot touch your toes.», reached through the same lesson line as the sentence the question matched. What matched: the same action «lean» (+2); the same property (+1). · the question and its options parsed, with trees and pragmatics
Test 3 · ★ · wrong ✗
A dad and a toddler want to balance on a seesaw. What works?
- 1. The toddler sits in the middle and the dad sits at the end — ← Mova's choice · no support
- 2. It cannot be done at all — no support
- 3. The dad sits at the very end — no support
- 4. The dad sits very close to the middle — ✓ 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 4 · ★ · wrong ✗
In a film a giant tall thin tower stands on one tiny point. What would really happen?
- 1. It would sink straight down into the ground — ← Mova's choice · no support
- 2. It would topple as soon as it leaned — ✓ the right answer · no support
- 3. It would stand there for ever without moving — no support
- 4. It would float slowly upwards into the clouds — 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 · ★ · right ✓
Why do you hold your arms out when walking along a narrow wall?
- 1. Like a pole, they help you correct wobbles — ← Mova's choice · ✓ the right answer · no support
- 2. They make you lighter — no support
- 3. They pull you to the ground — no support
- 4. They catch the wind like sails and lift you up a little — 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 6 · ★ · wrong ✗
What would happen to a ship with all its heavy cargo stacked high on deck?
- 1. It would go faster — ← Mova's choice · no support
- 2. It would be safer in a storm — no support
- 3. It would float much higher — no support
- 4. It would roll over more easily in a storm — ✓ 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 ✗
oi stop spinning, ur gonna fall over. why tho
- 1. Spinning pulls your blood up — ← Mova's choice · no support
- 2. The liquid in your ears keeps spinning and fools your brain — ✓ the right answer · no support
- 3. Spinning makes the floor tilt — no support
- 4. Spinning makes your legs heavier — 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 ✗
Your bag of shopping is heavy on the left. Which way do you lean?
- 1. You do not need to lean — ← Mova's choice · no support
- 2. To the right — ✓ the right answer · no support
- 3. Forwards — no support
- 4. To the left — 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 ✓
Why is balancing a pencil on your finger almost impossible?
- 1. It tips over too fast to correct — ← Mova's choice · ✓ the right answer · no support
- 2. It is too long and thin to see — no support
- 3. It is far too heavy — no support
- 4. Pencils have no centre of gravity — 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 ✓
A toy has a heavy bottom and is pushed over. What happens?
- 1. It rolls back upright — ← Mova's choice · ✓ the right answer · no support
- 2. It falls through the table — no support
- 3. It stays lying down — no support
- 4. It spins on its side — 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 11 · ★ · wrong ✗
Which stands most safely on a bus?
- 1. Feet together on tiptoe — ← Mova's choice · no support
- 2. Standing tall with feet close — no support
- 3. Feet wide apart, knees a bit bent — ✓ the right answer · no support
- 4. One foot, arms up — 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 1 · formal language · wrong ✗
Which of the following statements most accurately characterises the condition under which a body will be overturned?
- 1. It is touched by any external body — ← Mova's choice · no support
- 2. Its weight is concentrated at its lowest part — no support
- 3. Its height exceeds its width by any amount — no support
- 4. Its centre of gravity passes beyond the limits of its base — ✓ the right answer · 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 2 · formal language · right ✓
Identify the principal reason for which a tightrope performer carries an elongated pole.
- 1. The pole resists rapid rotation and so affords time for correction — ← Mova's choice · ✓ the right answer · no support
- 2. The pole diminishes the weight of the performer — no support
- 3. The pole conducts the performer's weight to the ground — no support
- 4. The pole is employed to propel the performer forwards — 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 two persons of unequal weight are to balance upon a seesaw. Determine the requisite disposition of the heavier person.
- 1. Directly above the pivot itself — no support
- 2. Nearer to the pivot than the lighter person — ← Mova's choice · ✓ the right answer · score 3
- 3. Further from the pivot than the lighter person — no support
- 4. At an equal distance from the pivot — 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 8, line 14: «On a seesaw, a heavy person near the middle can balance a light person far from the middle.», reached through the option's own match among the sentences about the question's things. What matched: the same doer «heavy person» (+2); the same property (+1). · the question and its options parsed, with trees and pragmatics
Exam question 4 · formal language · wrong ✗
Ascertain the organ chiefly responsible for informing the brain of the inclination of the body.
- 1. The skin of the feet — ← Mova's choice · no support
- 2. The stomach — no support
- 3. The lungs — no support
- 4. The inner ear — ✓ 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
This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/physics/8-balance-the-centre-of-gravity/