---
title: Ascertain the distance from the pivot at which a 40-kilogram child m… — Olympiad: forces, floating and machine… · tree and pragmatics
description: Ascertain the distance from the pivot at which a 40-kilogram child must sit to balance a 20-kilogram child seated 2 metres from it. Exam question 2 of lesson 42 «Olympiad: forces, floating and machines ★★★» of the physics course of Mova's primary school, with the dependency tree and pragmatics of th
---

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# Exam question 2 · Olympiad: forces, floating and machines ★★★

<!-- .ven lang=en -->
Ascertain the distance from the pivot at which a 40-kilogram child must sit to balance a 20-kilogram child seated 2 metres from it.

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 3 · wrong ✗ · **Who acts:** you, 40-kilogram child, 20-kilogram child · **What happens:** ascertain, sit, balance, seat · **To what, where:** distance, pivot, 20-kilogram child, 2 metres

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This is exam question 2 of lesson 42 «Olympiad: forces, floating and machines ★★★» of the physics course of Mova's primary school, asked in stiff, formal language. 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/42-olympiad-forces-floating-and-machines/#e2).

## The question {#question}

```conllu
# sent_id = question:physics:42-olympiad-forces-floating-and-machines:e2:1
# text = Ascertain the distance from the pivot at which a 40-kilogram child must sit to balance a 20-kilogram child seated 2 metres from it.
1	Ascertain	ascertain	VERB	VB	Mood=Imp|VerbForm=Fin	0	root	_	_
2	the	the	DET	DT	Definite=Def|PronType=Art	3	det	_	_
3	distance	distance	NOUN	NN	Number=Sing	1	obj	_	_
4	from	from	ADP	IN	_	6	case	_	_
5	the	the	DET	DT	Definite=Def|PronType=Art	6	det	_	_
6	pivot	pivot	NOUN	NN	Number=Sing	3	nmod	_	_
7	at	at	ADP	IN	_	8	case	_	_
8	which	which	PRON	WDT	PronType=Rel	13	obl	_	_
9	a	a	DET	DT	Definite=Ind|PronType=Art	11	det	_	_
10	40-kilogram	40-kilogram	NUM	CD	NumForm=Digit|NumType=Card	11	nummod	_	_
11	child	child	NOUN	NN	Number=Sing	13	nsubj	_	_
12	must	must	AUX	MD	VerbForm=Fin	13	aux	_	_
13	sit	sit	VERB	VB	VerbForm=Inf	6	acl:relcl	_	_
14	to	to	PART	TO	_	15	mark	_	_
15	balance	balance	VERB	VB	VerbForm=Inf	13	xcomp	_	_
16	a	a	DET	DT	Definite=Ind|PronType=Art	18	det	_	_
17	20-kilogram	20-kilogram	NUM	CD	NumForm=Digit|NumType=Card	18	nummod	_	_
18	child	child	NOUN	NN	Number=Sing	15	obj	_	_
19	seated	seat	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	18	acl	_	_
20	2	2	NUM	CD	NumForm=Digit|NumType=Card	21	nummod	_	_
21	metres	metre	NOUN	NNS	Number=Plur	19	obl:unmarked	_	_
22	from	from	ADP	IN	_	23	case	_	_
23	it	it	PRON	PRP	Case=Acc|Gender=Neut|Number=Sing|Person=3|PronType=Prs	19	obl	_	SpaceAfter=No
24	.	.	PUNCT	.	_	1	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **ascertain** | imperative | you *not said here* | the distance |  | the pivot |  |  | vn discover-84 «NP V NP»: agent=Agent distance=Topic |
| 2 | **sit** | must | a 40-kilogram child |  |  | the pivot |  |  | tree rules |
| 3 | **balance** | to-infinitive | a 40-kilogram child *not said here* | a 20-kilogram child |  |  |  |  | vn spatial\_configuration-47.6-1 «PP.location V NP»: agent=Location child=Theme |
| 4 | **seat** | participle | a 20-kilogram child *not said here* | 2 metres |  |  |  | from child | vn fit-54.3 «NP.location V NP»: agent=Location |

<!-- .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.

## The options {#options}

### Option 1 · ← Mova's choice {#o1}

<!-- .ven lang=en -->
4 metres

```conllu
# sent_id = question:physics:42-olympiad-forces-floating-and-machines:e2:o1:1
# text = 4 metres
1	4	4	NUM	CD	NumForm=Digit|NumType=Card	2	nummod	_	_
2	metres	metre	NOUN	NNS	Number=Plur	0	root	_	_
```

<!-- .note -->
The frames reader finds no event or fact in this sentence.

### Option 2 {#o2}

<!-- .ven lang=en -->
2 metres

```conllu
# sent_id = question:physics:42-olympiad-forces-floating-and-machines:e2:o2:1
# text = 2 metres
1	2	2	NUM	CD	NumForm=Digit|NumType=Card	2	nummod	_	_
2	metres	metre	NOUN	NNS	Number=Plur	0	root	_	_
```

<!-- .note -->
The frames reader finds no event or fact in this sentence.

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

<!-- .ven lang=en -->
1 metre

```conllu
# sent_id = question:physics:42-olympiad-forces-floating-and-machines:e2:o3:1
# text = 1 metre
1	1	1	NUM	CD	NumForm=Digit|NumType=Card	2	nummod	_	_
2	metre	metre	NOUN	NN	Number=Sing	0	root	_	_
```

<!-- .note -->
The frames reader finds no event or fact in this sentence.

### Option 4 {#o4}

<!-- .ven lang=en -->
Half a metre

```conllu
# sent_id = question:physics:42-olympiad-forces-floating-and-machines:e2:o4:1
# text = Half a metre
1	Half	half	DET	PDT	NumForm=Word|NumType=Frac|PronType=Ind	3	det:predet	_	_
2	a	a	DET	DT	Definite=Ind|PronType=Art	3	det	_	_
3	metre	metre	NOUN	NN	Number=Sing	0	root	_	_
```

<!-- .note -->
The frames reader finds no event or fact in this sentence.

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**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.

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- ← previous: [Olympiad: forces, floating and machine…, exam 1](https://md.mova.elamur.ai/free/en/corpora/questions/physics/42-olympiad-forces-floating-and-machines/e1/)
- next →: [Olympiad: forces, floating and machine…, exam 3](https://md.mova.elamur.ai/free/en/corpora/questions/physics/42-olympiad-forces-floating-and-machines/e3/)
- ↑ back to [Olympiad: forces, floating and machines ★★★](https://md.mova.elamur.ai/free/en/corpora/questions/physics/42-olympiad-forces-floating-and-machines/)