Simple machines and how they help

Tests: 8 of 12 right · Exam: 2 of 4 right · Kind: ★ · Understood: 10 of 16 · Run: 2026-10-18, commit f3c23ea72

Lesson 52 of the world 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 · ★ · right ✓

A girl and her much heavier father sit on a see-saw. How can they balance?

1. They can never balance — no support
2. The father sits right at the very end of the board — no support
3. The father sits closer to the middle — ← Mova's choice · ✓ the right answer · score 8
4. The girl sits closer to the middle — score 8

Why: It took the question to ask what something is like. 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 52, line 2: «A lever is a stiff bar that turns around a point called the pivot. If you push far from the pivot, a small force can lift a heavy load that sits close to the p…», reached through the remembered sentence the question matched. What matched: it fills the role the question asks for (+6); the same action «sit» (+2); the same property (+2). Against it: a different doer (counts against) (-2). · the question and its options parsed, with trees and pragmatics

Test 2 · ★ · right ✓

Which is true about every simple machine?

1. It may save force, but you must move further — ← Mova's choice · ✓ the right answer · score 8
2. It always produces more work than you put into it — score 8
3. It works without anyone pushing or pulling — no support
4. It makes loads lose their weight — score 4

Why: It took the question to ask which statement is true. It chose option 1 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 52, line 15: «A machine that saves force always makes you move further; it never saves work for free.», reached through the remembered sentence the question matched. What matched: the same action «save» (+4); the same doer «machine» (+2); the same thing acted on «force» (+2). · the question and its options parsed, with trees and pragmatics

Test 3 · ★ · wrong ✗

A worker must get a heavy barrel onto a lorry. Which helps most without a crane?

1. Lifting it with a much shorter plank — ← Mova's choice · no support
2. Rolling it up a long plank as a ramp — ✓ the right answer · no support
3. Dragging it along the rough gravel first — no support
4. Pushing it down from the top of the lorry — 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 4 · ★ · wrong ✗

Why is a long spanner better than a short one for undoing a stiff nut?

1. A long spanner removes friction from the nut — ← Mova's choice · no support
2. You push further from the nut, so you need less force — ✓ the right answer · no support
3. A long spanner makes the nut smaller — no support
4. A long spanner is made of stronger metal — 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 5 · ★ · wrong ✗

A pulley is fixed at the top of a well. What is the main help it gives?

1. The water becomes lighter to lift — ← Mova's choice · no support
2. The bucket becomes half as heavy — no support
3. The rope lifts the full bucket up the well all by itself — no support
4. You can pull down on the rope to raise the bucket — ✓ 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 6 · ★ · right ✓

A ramp is made longer and less steep. What happens to the push needed?

1. Smaller, but over a longer path — ← Mova's choice · ✓ the right answer · score 5
2. It becomes zero, with no push needed at all — no support
3. It becomes bigger and the path is shorter — no support
4. It stays exactly the same as before — no support

Why: It took the question to ask which statement is true. It chose option 1 with score 5, the only option with support. Its support: lesson 52, line 3: «Machines do not give us free work: to use less force we must push over a longer distance. Walking up a long gentle ramp is easier than climbing a steep ladder,…», reached through the same lesson line as the sentence the question matched. What matched: the same doer «path» (+4); the same property (+1). · the question and its options parsed, with trees and pragmatics

Test 7 · ★ · right ✓

Why does a steering wheel have a large rim instead of a small one?

1. A big wheel keeps the car on the road — no support
2. A big wheel turns the thin shaft with a stronger force — ← Mova's choice · ✓ the right answer · score 3
3. A big wheel makes the car lighter — no support
4. A big wheel makes the car go faster — no support

Why: It took the question to ask why something happens (its cause). It chose option 2 with score 3, the only option with support. Its support: lesson 52, line 11: «A wheel and axle turns a small force on a big wheel into a stronger turn on the thin axle.», reached through the option's own match among the sentences about the question's things. What matched: the same action «turn» (+3); a different thing acted on (counts against) (+1). Against it: the same doer «wheel» (-1). · the question and its options parsed, with trees and pragmatics

Test 8 · ★ · right ✓

If you move the pivot of a lever closer to the heavy load, what happens?

1. The load becomes heavier — score 2
2. Lifting the load needs less force — ← Mova's choice · ✓ the right answer · score 9
3. Nothing changes at all — no support
4. Lifting the load needs more force — score 9

Why: It took the question to ask what happens next. It chose option 2 with score 9, tied with another option at 9 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 52, line 10: «A ramp lets you lift a load with less force by moving it along a longer path.», reached through what followed the sentence the question matched. What matched: the same action «lift» (+5); the same thing acted on «load» (+4). · the question and its options parsed, with trees and pragmatics

Test 9 · ★ · right ✓

why push a heavy box up a ramp not just lift it

1. The ramp saves both force and distance at the same time — no support
2. The ramp needs less force but a longer path — ← Mova's choice · ✓ the right answer · score 5
3. The ramp pulls the box up itself — no support
4. The ramp makes the box lighter — 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 52, line 8: «The further from the pivot you push, the less force you need to lift a load.», reached through the same lesson line as the sentence the question matched. What matched: the same action «need» (+4); the same thing acted on «less force» (+2). Against it: a different doer (counts against) (-1). · the question and its options parsed, with trees and pragmatics

Test 10 · ★ · wrong ✗

door handle far from the hinge, why tho

1. It looks nicer on the door — ← Mova's choice · no support
2. It stops the door from closing — no support
3. The hinge would break if the handle were any nearer — no support
4. Pushing further from the pivot needs less force — ✓ the right answer · 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 11 · ★ · right ✓

my mate says a pulley always makes lifting lighter. true?

1. No, a pulley makes lifting heavier — no support
2. Yes, pulleys make loads lighter — no support
3. Yes, any pulley halves the weight — no support
4. No, one fixed pulley only changes the direction of the pull — ← Mova's choice · ✓ the right answer · score 3

Why: It took the question to ask which statement is true. It chose option 4 with score 3, the only option with support. Its support: lesson 52, line 13: «A single fixed pulley changes the direction of the pull but not its size.», reached through the option's own match among the sentences about the question's things. What matched: the same action «change» (+1); the same doer «single fixed pulley» (+1); the same thing acted on «direction» (+1). · the question and its options parsed, with trees and pragmatics

Test 12 · ★ · right ✓

a video said a clever machine can give you more work than you put in. right?

1. Yes, if the machine is big enough — no support
2. No, machines always waste every bit of the work you put in — score 2
3. Yes, levers make free work — score 4
4. No, a machine that saves force makes you move further — ← Mova's choice · ✓ the right answer · score 10

Why: It took the question to ask which statement is true. It chose option 4 with score 10, against 4 for the next best. Its support: lesson 52, line 15: «A machine that saves force always makes you move further; it never saves work for free.», reached through the same lesson line as the sentence the question matched. What matched: the same action «save» (+4); the same doer «machine» (+4); the same thing acted on «force» (+2). · 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 function of a simple machine?

1. It eliminates the necessity of any applied force whatsoever — ← Mova's choice · no support
2. It diminishes the mass of the load to be displaced — no support
3. It produces a greater quantity of work than is supplied to it — no support
4. It alters the magnitude or the direction of an applied force — ✓ 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

Exam question 2 · formal language · right ✓

It is given that a load is raised by means of a lever. Ascertain the condition under which the least effort shall be required.

1. The effort is applied at the greatest distance from the pivot — ← Mova's choice · ✓ the right answer · no support
2. The load is positioned at the greatest distance from the pivot — no support
3. The pivot is situated at the extremity of the bar — no support
4. The effort is applied immediately adjacent to the pivot — 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 3 · formal language · wrong ✗

Identify the principal advantage conferred by an inclined plane in respect of the elevation of a heavy load.

1. The friction upon the load is entirely abolished — no support
2. The weight of the load is permanently diminished — no support
3. A lesser force suffices, the load being conveyed along a longer path — ✓ the right answer · score 3
4. The load is elevated through a shorter path with greater force — ← Mova's choice · score 6

Why: It took the question to ask which statement is true. It chose option 4 with score 6, against 3 for the next best. Its support: lesson 52, line 2: «A lever is a stiff bar that turns around a point called the pivot. If you push far from the pivot, a small force can lift a heavy load that sits close to the p…», reached through the remembered sentence the question matched. What matched: the same action «lift» (+4); the same thing acted on «heavy load» (+2). The right option, 3, scored 3. · the question and its options parsed, with trees and pragmatics

Exam question 4 · formal language · right ✓

Select the response that is consistent with the established facts concerning a single fixed pulley.

1. It alters the direction of the pull but not its magnitude — ← Mova's choice · ✓ the right answer · score 5
2. It reduces the required pull to one half of the load — no support
3. It increases the required pull to twice the load — no support
4. It alters neither the direction nor the magnitude of the pull — score 5

Why: It took the question to ask which statement is true. It chose option 1 with score 5, tied with another option at 5 (the first shown, or the one claiming less beyond what it knows, wins). Its support: lesson 52, line 5: «A pulley is a wheel with a rope over it. One fixed pulley changes the direction of the force, so you can pull down to lift up; several pulleys together let a s…», reached through the same lesson line as the sentence the question matched. What matched: the same action «change» (+4); the same thing acted on «direction» (+2). Against it: a different doer (counts against) (-1). · the question and its options parsed, with trees and pragmatics

This page in Markdown → https://md.mova.elamur.ai/free/en/school-run/world/52-simple-machines/