---
title: Speed: fast and slow — how Mova does on the tests · Physics
description: Lesson 36 of the physics course of Mova's primary school: 5 of 11 tests right, exam 0 of 4, every question with the options, the student's choice, the right answer and why it chose.
---

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# Speed: fast and slow

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**Tests:** 5 of 11 right · **Exam:** 0 of 4 right · **Kind:** plain · **Understood:** 7 of 15 · **Run:** 2026-10-18, commit `f3c23ea72`

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Lesson 36 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](https://md.mova.elamur.ai/free/en/corpora/school/physics/36-speed-fast-and-slow/).

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Every question of this lesson and each of its options parsed by Mova, with trees and pragmatics: [the lesson's questions in the corpora](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/).

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### Test 1 · right ✓ {#t1}

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bro said if u drop a ball on a moving train it'll fly to the back. true??

- **1.** No, it lands at your feet; it is moving with the train — **← Mova's choice** · **✓ the right answer** · score 9
- **2.** Yes, it shoots backwards really fast as the train speeds on — score 2
- **3.** No, it floats in the air — no support
- **4.** Yes, the train moves away from it — no support

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**Why:** It took the question to ask which statement is true. It chose option 1 with score 9, against 2 for the next best. Its support: lesson 36, line 10: «A ball dropped on a smooth train lands at your feet because it was already moving with the train.», reached through the option's own match among the sentences about the question's things. What matched: the same action «land» (+4); the same doer «ball» (+3); the same place «feet» (+2). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/t1/)

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### Test 2 · wrong ✗ {#t2}

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Why does a plane high in the sky look like it is crawling, though it goes about 900 kilometres an hour?

- **1.** It is so far away that it seems to move slowly — **✓ the right answer** · no support
- **2.** It really does fly slowly when it is up that high — **← Mova's choice** · score 5
- **3.** The clouds and the thin air hold it back up there — no support
- **4.** It is actually going backwards against the strong wind — no support

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**Why:** It took the question to ask why something happens (its cause). It chose option 2 with score 5, the only option with support. Its support: lesson 36, line 16: «A passenger plane flies at about 900 kilometres an hour, many times faster than a car, yet high in the sky it is so far away that it seems to crawl.», reached through the option's own match among the sentences about the question's things. What matched: the same action «fly» (+3); the same doer «passenger plane» (+2). The right option, 1, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/t2/)

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### Test 3 · right ✓ {#t3}

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In a cartoon, a car brakes hard and the passengers are thrown backwards. What's wrong?

- **1.** Nothing, braking throws you backwards — no support
- **2.** They would stay perfectly still — no support
- **3.** They would lurch forward, because their bodies keep moving — **← Mova's choice** · **✓ the right answer** · score 7
- **4.** They would float upwards — no support

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**Why:** It took the question to ask which statement is true. It chose option 3 with score 7, the only option with support. Its support: lesson 36, line 11: «When a car brakes, your body keeps moving forward; when it turns sharply, you lurch outwards.», reached through a sentence linked to the one the question matched. What matched: the same action «keep» (+4); the same doer «body» (+3). · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/t3/)

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### Test 4 · wrong ✗ {#t4}

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Uncle Joe says driving twice as fast only needs twice the stopping distance. Put him right.

- **1.** It needs about four times the distance — **✓ the right answer** · no support
- **2.** He is right, it is exactly twice as far — no support
- **3.** It needs only half the distance, since you go faster — **← Mova's choice** · score 8
- **4.** It needs the very same distance as before — score 8

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**Why:** It took the question to ask which statement is true. It chose option 3 with score 8, tied with another option at 8 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 36, line 7: «To compare speeds you need both the distance and the time; the winner of a race covers the distance in the least time.», reached through the option's own match among the sentences about the question's things. What matched: the same action «need» (+4); the same thing acted on «distance» (+4). The right option, 1, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/t4/)

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### Test 5 · right ✓ {#t5}

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Ella wants to try the tablecloth trick with Gran's best plates. What's the sensible advice?

- **1.** Practise with plastic cups; a slow pull drags dishes off — **← Mova's choice** · **✓ the right answer** · no support
- **2.** Use a tablecloth that is wet — no support
- **3.** Go ahead, it always works — no support
- **4.** Go ahead, a slow careful pull is safest — no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/t5/)

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### Test 6 · right ✓ {#t6}

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When a car turns sharply left, which way does your body lurch?

- **1.** Outwards, to the right — **← Mova's choice** · **✓ the right answer** · no support
- **2.** Backwards, towards the boot — no support
- **3.** Straight down into the seat — no support
- **4.** Inwards, to the left side — no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/t6/)

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### Test 7 · wrong ✗ {#t7}

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A snail goes a metre in a few minutes. Which is true?

- **1.** Snails go about 100 kilometres an hour — **← Mova's choice** · no support
- **2.** A cheetah could cover the same metre in a blink — **✓ the right answer** · no support
- **3.** A snail never moves at all — no support
- **4.** A snail is faster than a person walking along the pavement — no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/t7/)

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### Test 8 · wrong ✗ {#t8}

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just shut up and drive, I'm texting, it's fine. is it?

- **1.** Yes, texting doesn't count as driving — **← Mova's choice** · no support
- **2.** Yes, phones make drivers react faster — no support
- **3.** Yes, if the car is slow — no support
- **4.** No, drivers on phones react later and travel further before braking — **✓ the right answer** · no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/t8/)

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### Test 9 · right ✓ {#t9}

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Two runners both run 100 metres. Ana takes 15 seconds, Ben takes 18. Who is faster?

- **1.** Ana — **← Mova's choice** · **✓ the right answer** · no support
- **2.** Ben — no support
- **3.** You cannot tell without their weight — no support
- **4.** They are equally fast — no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/t9/)

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### Test 10 · wrong ✗ {#t10}

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What would happen if you ran straight on ice and tried to turn sharply?

- **1.** You would stop at once — **← Mova's choice** · no support
- **2.** Your feet would slide, with no grip to push you round — **✓ the right answer** · no support
- **3.** You would turn more easily than on grass — no support
- **4.** You would fly upwards — no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/t10/)

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### Test 11 · wrong ✗ {#t11}

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A full lorry and an empty one have the same engine. Which speeds up faster?

- **1.** The full lorry — score -2
- **2.** Neither can speed up — no support
- **3.** The empty lorry — **✓ the right answer** · score -2
- **4.** Both the same — **← Mova's choice** · score 1

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**Why:** It took the question to ask who or what does it. It chose option 4 with score 1, against -2 for the next best. Its support: lesson 36, line 13: «A lighter car speeds up faster than a heavy lorry with the same engine.», reached through the remembered sentence the question matched. What matched: the same action «speed up» (+1). The right option, 3, scored -2. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/t11/)

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### Exam question 1 · formal language · wrong ✗ {#e1}

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Identify the quantities which must be known in order to determine the speed of a moving body.

- **1.** The mass of the body together with its colour — no support
- **2.** The distance travelled and the time taken — **✓ the right answer** · no support
- **3.** The height of the body above the ground — no support
- **4.** The time taken alone — **← Mova's choice** · score 8

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**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 36, line 7: «To compare speeds you need both the distance and the time; the winner of a race covers the distance in the least time.», reached through the option's own match among the sentences about the question's things. What matched: the same action «need» (+4); the same thing acted on «distance» (+4). The right option, 2, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/e1/)

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### Exam question 2 · formal language · wrong ✗ {#e2}

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Ascertain the approximate factor by which the braking distance of a vehicle increases when its speed is doubled.

- **1.** It remains unaltered — **← Mova's choice** · no support
- **2.** Approximately fourfold — **✓ the right answer** · no support
- **3.** Approximately twofold — no support
- **4.** It is reduced by one half — no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/e2/)

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### Exam question 3 · formal language · wrong ✗ {#e3}

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Which of the following statements most accurately characterises the forward motion of a passenger when a vehicle decelerates abruptly?

- **1.** The brakes attract the passenger towards the front — **← Mova's choice** · score 5
- **2.** The body of the passenger tends to continue in its state of motion — **✓ the right answer** · no support
- **3.** The seat exerts a forward force upon the passenger — no support
- **4.** The air contained within the vehicle propels the passenger forwards — no support

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**Why:** It took the question to ask who or what does it. It chose option 1 with score 5, the only option with support. Its support: lesson 9, line 5: «Gears, brakes and tyres follow simple rules too: a low gear makes hills easy, and slamming on only the front brake can throw you over the handlebars.», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+5); the same doer «gears» (+3). Against it: a different thing acted on (counts against) (-3). The right option, 2, found no support in what it remembers. · [the question and its options parsed, with trees and pragmatics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/e3/)

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### Exam question 4 · formal language · wrong ✗ {#e4}

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Select the response consistent with the established facts concerning the use of telephones by drivers.

- **1.** It enhances the alertness of the driver — **← Mova's choice** · no support
- **2.** It delays the reaction of the driver and so lengthens the distance travelled before braking — **✓ the right answer** · no support
- **3.** It causes the brakes of the vehicle to fail — no support
- **4.** It has no bearing whatsoever upon stopping distance — no support

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**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](https://md.mova.elamur.ai/free/en/corpora/questions/physics/36-speed-fast-and-slow/e4/)

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- ← previous: [35. Pulleys, gears and big machines](https://md.mova.elamur.ai/free/en/school-run/physics/35-pulleys-gears-and-big-machines/)
- next →: [37. Seat belts, crashes and keeping safe](https://md.mova.elamur.ai/free/en/school-run/physics/37-seat-belts-crashes-and-keeping-safe/)
- ↑ back to [Physics](https://md.mova.elamur.ai/free/en/school-run/physics/)