What sound is: wobbles in the air

Tests: 3 of 11 right · Exam: 0 of 4 right · Kind: plain · Understood: 8 of 15 · Run: 2026-10-18, commit f3c23ea72

Lesson 17 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 ✗

In a space film a spaceship explodes with a huge boom. What is wrong with that?

1. Nothing, explosions are always loud — ← Mova's choice · no support
2. There is no air in space to carry sound — ✓ the right answer · no support
3. Space makes sounds louder, not quieter — no support
4. Only small explosions are silent in space — 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 2 · wrong ✗

me mate reckons whales just splash about, they can't hear each other far. right?

1. Yes, whales are deaf — ← Mova's choice · no support
2. No, their songs travel hundreds of kilometres under water — ✓ the right answer · no support
3. No, but only in warm seas — no support
4. Yes, sound stops a few metres under water — 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 ✗

You blow across bottles with different amounts of water and hear different notes. Which idea does this show?

1. Different-sized wobbles make different notes — ✓ the right answer · score 3
2. Water makes all sounds the same — ← Mova's choice · score 7
3. The water itself sings — score 4
4. Bottles only make a sound when they are completely empty — no support

Why: It took the question to ask who or what does it. It chose option 2 with score 7, against 4 for the next best. Its support: lesson 16, line 8: «In soapy water the air escaping from a punctured tube makes bubbles that show where the hole is.», reached through the option's own match among the sentences about the question's things. What matched: it fills the role the question asks for (+3); the same action «make» (+2); the same doer «air» (+2). The right option, 1, scored 3. · the question and its options parsed, with trees and pragmatics

Test 4 · wrong ✗

What would happen to a guitar if its strings were made very slack and loose?

1. Its notes would sound higher — ← Mova's choice · score 2
2. Its notes would sound lower — ✓ the right answer · score 2
3. It would make no sound at all — no support
4. It would sound exactly the same — no support

Why: It took the question to ask what happens next. It chose option 1 with score 2, tied with another option at 2 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 17, line 10: «Short, thin, tight strings wobble fast and sound high; long, thick, slack strings wobble slowly and sound low; blowing across bottles with different amounts of…», reached through the option's own match among the sentences about the question's things. What matched: the same action «sound» (+2); the same property (+1). Against it: a different doer (counts against) (-1). The right option, 2, scored 2. · the question and its options parsed, with trees and pragmatics

Test 5 · right ✓

In a cartoon, a character shouts and the words visibly fly through the air as letters. What really travels?

1. The words themselves as invisible letters — no support
2. Little puffs of light — no support
3. A wobble in the air — ← Mova's choice · ✓ the right answer · score 8
4. Tiny bits of the voice — score 6

Why: It took the question to ask what it is done to. It chose option 3 with score 8, against 6 for the next best. Its support: lesson 17, line 6: «Sound is a wobble, or vibration, passed on through air, water or solid things.», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+6); the same thing acted on «wobble» (+4). Against it: a different action (counts against) (-2). · the question and its options parsed, with trees and pragmatics

Test 6 · wrong ✗

Why do concert halls have special shapes and soft materials?

1. To make the hall look bigger — ← Mova's choice · no support
2. To stop the sound reaching the audience — no support
3. To keep the musicians warm — no support
4. To control how sound bounces so the music sounds right — ✓ 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 · right ✓

shut it, you can't hear nothing under water, everyone knows that

1. Right, only fish can make sound — no support
2. Right, water blocks all sound — no support
3. Wrong, but only for very loud bangs — no support
4. Wrong, sound travels well under water, even better than in air — ← Mova's choice · ✓ the right answer · score 8

Why: It took the question to ask which statement is true. It chose option 4 with score 8, the only option with support. Its support: lesson 17, line 16: «Sound travels further and faster in water than in air, and whale songs can carry hundreds of kilometres.», reached through the remembered sentence the question matched. What matched: the same place «water» (+4); the same action «travel» (+3); the same doer «sound» (+1). · the question and its options parsed, with trees and pragmatics

Test 8 · right ✓

Doctors want to see a baby inside its mum without any cuts. What do they use?

1. A bright torch shone straight through the skin of the tummy — no support
2. A magnet and a compass — score 4
3. Loud music played into the tummy — no support
4. Ultrasound, very high sounds and their echoes — ← Mova's choice · ✓ the right answer · score 16

Why: It took the question to ask what it is done to. It chose option 4 with score 16, against 4 for the next best. Its support: lesson 17, line 14: «Ships use echoes under water, called sonar, and doctors use very high sounds, called ultrasound, to see inside the body.», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+6); the same thing acted on «high sounds» (+4); the same action «use» (+3); the same doer «doctors» (+3). · the question and its options parsed, with trees and pragmatics

Test 9 · wrong ✗

Your new bedroom is empty and echoey. What would make it quieter?

1. Painting all four walls a much darker colour — ← Mova's choice · no support
2. Opening all the windows — no support
3. Adding curtains, a rug and soft furniture — ✓ the right answer · no support
4. Taking out the light bulb — 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 ✗

Which shows that you must have something wobbling to make a sound?

1. Light shines without making any sound — no support
2. A drum stops sounding when you hold its skin still — ✓ the right answer · no support
3. A cold room is always quieter than a warm one with the heating on — ← Mova's choice · score 5
4. Shadows make no noise at all — no support

Why: It took the question to ask who or what does it. It chose option 3 with score 5, the only option with support. Its support: lesson 17, line 12: «Hard bare walls bounce sound back, while soft curtains, carpets and sofas soak it up, so a furnished room hardly echoes.», reached through a sentence linked to the one the question matched. What matched: it fills the role the question asks for (+3); the same doer «furnished room» (+2). The right option, 2, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Test 11 · wrong ✗

Your gran says she cannot hear the high beep of the oven any more but you can. Why?

1. Her oven makes two different beeps — no support
2. The beep is too low for older people — ← Mova's choice · score 4
3. Hearing of high notes fades with age — ✓ the right answer · no support
4. Children's ears are louder — no support

Why: It took the question to ask why something happens (its cause). It chose option 2 with score 4, the only option with support. Its support: lesson 17, line 15: «Dogs can hear much higher notes than people can, and people hear the highest notes less and less as they grow older.», reached through the cause of the sentence the question matched. What matched: the same circumstance (+5). Against it: 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

Exam question 1 · formal language · wrong ✗

Which of the following statements most accurately characterises the phenomenon of sound?

1. It is a stream of particles emitted by the source — ← Mova's choice · no support
2. It is a property solely of the human ear — no support
3. It is a vibration transmitted through a material medium — ✓ the right answer · no support
4. It is a form of light perceptible to the ear — 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 reason for which sound cannot be transmitted through the vacuum of space.

1. The temperature of space is excessively low for any vibration — no support
2. Sound is absorbed by the light of the Sun — ← Mova's choice · score 5
3. The radiation of the stars obstructs it — no support
4. There exists no medium to transmit the vibration — ✓ the right answer · no support

Why: It took the question to ask which statement is true. It chose option 2 with score 5, the only option with support. Its support: lesson 17, line 12: «Hard bare walls bounce sound back, while soft curtains, carpets and sofas soak it up, so a furnished room hardly echoes.», reached through the remembered sentence the question matched. What matched: the same action «soak up» (+3); the same thing acted on «sound» (+3). Against it: a different doer (counts against) (-1). The right option, 4, found no support in what it remembers. · the question and its options parsed, with trees and pragmatics

Exam question 3 · formal language · wrong ✗

It is given that a string is shortened and tightened. Determine the consequent alteration in its pitch.

1. The pitch is lowered — ← Mova's choice · no support
2. The pitch is raised — ✓ the right answer · no support
3. The string ceases to produce sound — no support
4. The pitch is unaltered — 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 ✗

Identify the means by which a bat determines the position of obstacles in darkness.

1. By vision unaffected by the absence of light — ← Mova's choice · no support
2. By the reception of echoes of its own high-pitched calls — ✓ the right answer · no support
3. By the sense of smell alone — no support
4. By memory of all previous flights — 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/17-what-sound-is-wobbles-in-the-air/