---
title: Why do skateboards spin for ages but an old cart wheel creaks to a s… — Living with friction: oil, wheels and… · tree and pragmatics
description: Why do skateboards spin for ages but an old cart wheel creaks to a stop? Test 10 · ★ of lesson 7 «Living with friction: oil, wheels and grip» 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 right.
---

<!-- md -->
[Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/questions/physics/7-living-with-friction/t10/)

<!-- 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/) / [Living with friction: oil, wheels and…](https://md.mova.elamur.ai/free/en/corpora/questions/physics/7-living-with-friction/) / t10

# Test 10 · ★ · Living with friction: oil, wheels and grip

<!-- .ven lang=en -->
Why do skateboards spin for ages but an old cart wheel creaks to a stop?

<!-- .vintro -->
**Mova's choice:** option 1 · **The right answer:** option 1 · right ✓ · **Who acts:** skateboards, old cart wheel · **What happens:** spin, creak

<!-- .vabout -->
This is test 10 · ★ of lesson 7 «Living with friction: oil, wheels and grip» 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/7-living-with-friction/#t10).

## The question {#question}

```conllu
# sent_id = question:physics:7-living-with-friction:t10:1
# text = Why do skateboards spin for ages but an old cart wheel creaks to a stop?
1	Why	why	ADV	WRB	PronType=Int	4	advmod	_	_
2	do	do	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	4	aux	_	_
3	skateboards	skateboard	NOUN	NNS	Number=Plur	4	nsubj	_	_
4	spin	spin	VERB	VB	VerbForm=Inf	0	root	_	_
5	for	for	ADP	IN	_	6	case	_	_
6	ages	age	NOUN	NNS	Number=Plur	4	obl	_	_
7	but	but	CCONJ	CC	_	12	cc	_	_
8	an	a	DET	DT	Definite=Ind|PronType=Art	11	det	_	_
9	old	old	ADJ	JJ	Degree=Pos	11	amod	_	_
10	cart	cart	NOUN	NN	Number=Sing	11	compound	_	_
11	wheel	wheel	NOUN	NN	Number=Sing	12	nsubj	_	_
12	creaks	creak	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	4	conj	_	_
13	to	to	ADP	IN	_	15	case	_	_
14	a	a	DET	DT	Definite=Ind|PronType=Art	15	det	_	_
15	stop	stop	NOUN	NN	Number=Sing	12	obl	_	SpaceAfter=No
16	?	?	PUNCT	.	_	4	punct	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **spin** | present · do-support | skateboards |  |  |  | for ages |  | vn create-26.4-1-1 «NP V NP PP.beneficiary»: agent=Agent for age=Beneficiary |
| 2 | **creak** | present | a old cart wheel |  |  |  |  | to a stop | vn sound\_emission-43.2 «NP V»: agent=Theme |

<!-- .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 · ✓ the right answer {#o1}

<!-- .ven lang=en -->
Ball bearings roll instead of rub

```conllu
# sent_id = question:physics:7-living-with-friction:t10:o1:1
# text = Ball bearings roll instead of rub
1	Ball	ball	NOUN	NN	Number=Sing	2	compound	_	_
2	bearings	bearing	NOUN	NNS	Number=Plur	3	nsubj	_	_
3	roll	roll	VERB	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	instead	instead	ADV	RB	ExtPos=ADP	6	case	_	_
5	of	of	ADP	IN	_	4	fixed	_	_
6	rub	rub	NOUN	NN	Number=Sing	3	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **roll** | present | Ball bearings |  |  |  |  | instead rub | vn run-51.3.2-2 «NP V»: agent=Theme |

### Option 2 {#o2}

<!-- .ven lang=en -->
Skateboards are pulled less by gravity

```conllu
# sent_id = question:physics:7-living-with-friction:t10:o2:1
# text = Skateboards are pulled less by gravity
1	Skateboards	skateboard	NOUN	NNS	Number=Plur	3	nsubj:pass	_	_
2	are	be	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	3	aux:pass	_	_
3	pulled	pull	VERB	VBN	Tense=Past|VerbForm=Part|Voice=Pass	0	root	_	_
4	less	less	ADV	RBR	Degree=Cmp	3	advmod	_	_
5	by	by	ADP	IN	_	6	case	_	_
6	gravity	gravity	NOUN	NN	Number=Sing	3	obl:agent	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **pull** | present · passive | gravity | Skateboards |  |  |  | less *property* | vn push-12-1 «NP V NP»: agent=Agent subject=Theme |

### Option 3 {#o3}

<!-- .ven lang=en -->
Old wood has no friction at all

```conllu
# sent_id = question:physics:7-living-with-friction:t10:o3:1
# text = Old wood has no friction at all
1	Old	old	ADJ	JJ	Degree=Pos	2	amod	_	_
2	wood	wood	NOUN	NN	Number=Sing	3	nsubj	_	_
3	has	have	VERB	VBZ	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	0	root	_	_
4	no	no	DET	DT	PronType=Neg	5	det	_	_
5	friction	friction	NOUN	NN	Number=Sing	3	obj	_	_
6	at	at	ADP	IN	_	7	case	_	_
7	all	all	DET	DT	PronType=Tot	5	nmod	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **have** | present | Old wood | no friction |  | all |  |  | vn birth-28.2-1 «NP V NP»: agent=Agent friction=Patient |

### Option 4 {#o4}

<!-- .ven lang=en -->
Cart wheels are heavier than skates

```conllu
# sent_id = question:physics:7-living-with-friction:t10:o4:1
# text = Cart wheels are heavier than skates
1	Cart	cart	NOUN	NN	Number=Sing	2	compound	_	_
2	wheels	wheel	NOUN	NNS	Number=Plur	4	nsubj	_	_
3	are	be	AUX	VBP	Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin	4	cop	_	_
4	heavier	heavy	ADJ	JJR	Degree=Cmp	0	root	_	_
5	than	than	ADP	IN	_	6	case	_	_
6	skates	skate	NOUN	NNS	Number=Plur	4	obl	_	_
```

<!-- .fr -->
| # | verb | tense, mood | who | what, whom | to whom | where | when | other | roles by |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | **is** | present | Cart wheels |  |  |  |  | than skates; heavy *property* | tree rules |

<!-- 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: [Living with friction: oil, wheels and…, test 9](https://md.mova.elamur.ai/free/en/corpora/questions/physics/7-living-with-friction/t9/)
- next →: [Living with friction: oil, wheels and…, exam 1](https://md.mova.elamur.ai/free/en/corpora/questions/physics/7-living-with-friction/e1/)
- ↑ back to [Living with friction: oil, wheels and grip](https://md.mova.elamur.ai/free/en/corpora/questions/physics/7-living-with-friction/)