---
title: A police car drives past you at speed. Which is true about its siren? — Thunder, sirens and how fast sound tra… · tree and pragmatics
description: A police car drives past you at speed. Which is true about its siren? Test 4 · ★ of lesson 18 «Thunder, sirens and how fast sound travels» of the physics course of Mova's primary school, with the dependency tree and pragmatics of the question and of each option; Mova's choice was wrong.
---

<!-- md -->
[Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/questions/physics/18-thunder-sirens-and-how-fast-sound-travels/t4/)

<!-- crumbs -->
[home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [questions](https://md.mova.elamur.ai/free/en/corpora/questions/) / [Physics](https://md.mova.elamur.ai/free/en/corpora/questions/physics/) / [Thunder, sirens and how fast sound tra…](https://md.mova.elamur.ai/free/en/corpora/questions/physics/18-thunder-sirens-and-how-fast-sound-travels/) / t4

# Test 4 · ★ · Thunder, sirens and how fast sound travels

<!-- .ven lang=en -->
A police car drives past you at speed. Which is true about its siren?

<!-- .vintro -->
**Mova's choice:** option 2 · **The right answer:** option 3 · wrong ✗ · **Who acts:** police car · **What happens:** drive, be · **To what, where:** speed

<!-- .vabout -->
This is test 4 · ★ of lesson 18 «Thunder, sirens and how fast sound travels» of the physics course of Mova's primary school. The page gives the question's syntax tree — a dependency tree in the style of Universal Dependencies — and its pragmatics clause by clause, then the 4 options as the student saw them, each with its tree and pragmatics. Every text is parsed by Mova itself. How the student answered it, with the score of every option and why: [the test at school](https://md.mova.elamur.ai/free/en/school-run/physics/18-thunder-sirens-and-how-fast-sound-travels/#t4).

## The question {#question}

<!-- .note -->
*Sentence 1:* A police car drives past you at speed.

```conllu
# sent_id = question:physics:18-thunder-sirens-and-how-fast-sound-travels:t4:1
# text = A police car drives past you at speed.
1	A	a	DET	DT	Definite=Ind|PronType=Art	3	det	_	_
2	police	police	NOUN	NN	Number=Sing	3	compound	_	_
3	car	car	NOUN	NN	Number=Sing	4	nsubj	_	_
4	drives	drive	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
5	past	past	ADP	IN	_	6	case	_	_
6	you	you	PRON	PRP	Case=Acc|Person=2|PronType=Prs	4	obl	_	_
7	at	at	ADP	IN	_	8	case	_	_
8	speed	speed	NOUN	NN	Number=Sing	4	obl	_	SpaceAfter=No
9	.	.	PUNCT	.	_	4	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **drive** | present | a police car |  |  | speed |  | past you | vn nonvehicle-51.4.2-1 «NP V PP.location»: agent=Agent past you=Trajectory |

<!-- .note -->
One row per clause the reader finds. «not said here»: a role filled from the clause above. «roles by»: a VerbNet class and frame when one fits the verb, else the reader's rules on the tree.

<!-- .note -->
*Sentence 2:* Which is true about its siren?

```conllu
# sent_id = question:physics:18-thunder-sirens-and-how-fast-sound-travels:t4:2
# text = Which is true about its siren?
1	Which	which	PRON	WDT	PronType=Rel	3	nsubj	_	_
2	is	be	AUX	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	3	cop	_	_
3	true	true	ADJ	JJ	Degree=Pos	0	root	_	_
4	about	about	ADP	IN	_	6	case	_	_
5	its	its	PRON	PRP$	Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs	6	nmod:poss	_	_
6	siren	siren	NOUN	NN	Number=Sing	3	obl	_	SpaceAfter=No
7	?	?	PUNCT	.	_	3	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | present |  |  |  |  |  | about speed's siren; true *property* | tree rules |

## The options {#options}

### Option 1 {#o1}

<!-- .ven lang=en -->
It sounds the same the whole time

```conllu
# sent_id = question:physics:18-thunder-sirens-and-how-fast-sound-travels:t4:o1:1
# text = It sounds the same the whole time
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	2	nsubj	_	_
2	sounds	sound	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	the	the	DET	DT	Definite=Def|PronType=Art	4	det	_	_
4	same	same	ADJ	JJ	Degree=Pos	2	obj	_	_
5	the	the	DET	DT	Definite=Def|PronType=Art	7	det	_	_
6	whole	whole	ADJ	JJ	Degree=Pos	7	amod	_	_
7	time	time	NOUN	NN	Number=Sing	2	obl:unmarked	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **sound** | present | It | the same |  |  | time |  | vn sound\_emission-43.2 «PP.location V NP»: agent=Location same=Theme |

### Option 2 · ← Mova's choice {#o2}

<!-- .ven lang=en -->
It sounds lower coming and higher going

```conllu
# sent_id = question:physics:18-thunder-sirens-and-how-fast-sound-travels:t4:o2:1
# text = It sounds lower coming and higher going
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	2	nsubj	_	_
2	sounds	sound	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	lower	low	ADJ	JJR	Degree=Cmp	2	xcomp	_	_
4	coming	come	VERB	VBG	Tense=Pres|VerbForm=Part	3	advcl	_	_
5	and	and	CCONJ	CC	_	6	cc	_	_
6	higher	high	ADJ	JJR	Degree=Cmp	3	conj	_	_
7	going	go	VERB	VBG	Tense=Pres|VerbForm=Part	3	advcl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **sound** | present | It |  |  |  |  | low *property* | vn stimulus\_subject-30.4 «NP V ADJ»: agent=Stimulus |
| 2 | **come** | gerund |  |  |  |  |  |  | vn escape-51.1-1 «NP V»: agent=Theme |
| 3 | **go** | gerund |  |  |  |  |  |  | vn disappearance-48.2-1 «NP V»: agent=Theme |

### Option 3 · ✓ the right answer {#o3}

<!-- .ven lang=en -->
It sounds higher coming and lower going

```conllu
# sent_id = question:physics:18-thunder-sirens-and-how-fast-sound-travels:t4:o3:1
# text = It sounds higher coming and lower going
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	2	nsubj	_	_
2	sounds	sound	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	higher	high	ADJ	JJR	Degree=Cmp	4	amod	_	_
4	coming	come	VERB	VBG	VerbForm=Ger	2	xcomp	_	_
5	and	and	CCONJ	CC	_	7	cc	_	_
6	lower	low	ADJ	JJR	Degree=Cmp	7	amod	_	_
7	going	go	VERB	VBG	VerbForm=Ger	4	conj	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **sound** | present | It |  |  |  |  |  | tree rules |
| 2 | **come** | gerund |  |  |  |  |  |  | vn escape-51.1-1 «NP V»: agent=Theme |
| 3 | **go** | gerund |  |  |  |  |  |  | vn disappearance-48.2-1 «NP V»: agent=Theme |

### Option 4 {#o4}

<!-- .ven lang=en -->
It goes silent as it passes

```conllu
# sent_id = question:physics:18-thunder-sirens-and-how-fast-sound-travels:t4:o4:1
# text = It goes silent as it passes
1	It	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	2	nsubj	_	_
2	goes	go	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
3	silent	silent	ADJ	JJ	Degree=Pos	2	xcomp	_	_
4	as	as	SCONJ	IN	_	6	mark	_	_
5	it	it	PRON	PRP	Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs	6	nsubj	_	_
6	passes	pass	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	2	advcl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **go** | present | It |  |  |  |  | silent *property* | vn disappearance-48.2-1 «NP V»: agent=Theme |
| 2 | **pass** | present | it |  |  |  |  |  | vn occur-48.3-1 «NP V»: agent=Theme |

<!-- div src -->

**Text:** the tests of Mova's primary school, written for Mova (`world/data/school/`), as the course runner gave them to the student. **Trees:** Mova's own parse — the `en` model on the CPU, when the site is built — not checked by a teacher; they may be wrong. **Frames:** Mova's frames reader (`prag`), each text read on its own. Elamur Cosmic License.

<!-- /div -->

<!-- pn -->
- ← previous: [Thunder, sirens and how fast sound tra…, test 3](https://md.mova.elamur.ai/free/en/corpora/questions/physics/18-thunder-sirens-and-how-fast-sound-travels/t3/)
- next →: [Thunder, sirens and how fast sound tra…, test 5](https://md.mova.elamur.ai/free/en/corpora/questions/physics/18-thunder-sirens-and-how-fast-sound-travels/t5/)
- ↑ back to [Thunder, sirens and how fast sound travels](https://md.mova.elamur.ai/free/en/corpora/questions/physics/18-thunder-sirens-and-how-fast-sound-travels/)