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G.C.E. O/L Physics · Grade 10

Newton's Laws of Motionநியூற்றனின் இயக்க விதிகள்චලිතය පිළිබඳ නිව්ටන් නියම

நியூற்றனின் இயக்க விதிகள்චලිතය පිළිබඳ නිව්ටන් නියම

Inertia, F = ma, action and reaction, and practical applications in transport and sports. This page is a free preview of the STEM Cloud lesson for Grade 10 G.C.E. Ordinary Level Physics in Sri Lanka: the key points, the formulas, a worked example and a short quiz, taken from the lesson itself.

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What you will learn

  • What is Force, and What Does It Do?விசை என்றால் என்ன? அது என்ன பண்ணும்?බලය යනු කුමක්ද, එය කරන්නේ කුමක්ද?
  • Newton's First Law — the Law of Laziness (Inertia)நியூற்றனின் முதலாவது விதி — சடத்துவம் (Inertia)!නිව්ටන්ගේ පළමු නියමය — කම්මැලිකමේ නියමය (අවස්ථිතිය)
  • Newton's Second Law — F = maநியூற்றனின் இரண்டாவது விதி — F = maනිව්ටන්ගේ දෙවන නියමය — F = ma
  • Newton's Third Law — Action and Reactionநியூற்றனின் மூன்றாவது விதி — தாக்கமும் மறுதாக்கமும்නිව්ටන්ගේ තුන්වන නියමය — ක්‍රියාව සහ ප්‍රතික්‍රියාව
  • Momentum — Mass and Velocity Togetherஉந்தம் (Momentum) — திணிவும் வேகமும் சேர்ந்துගම්‍යතාව — ස්කන්ධය සහ ප්‍රවේගය එකට
  • Mass and Weight — Not the Same Thing!திணிவும் நிறையும் — இது ஒண்ணும் ஒண்ணு இல்ல!ස්කන්ධය සහ බර — එක ම දෙයක් නොවේ!

Key points to remember

  • Newton's first law: a body stays at rest, or keeps moving at uniform velocity, until an unbalanced force acts on it.
    நியூற்றனின் முதலாவது விதி: சமநிலைப்படுத்தப்படாத விசை பிரயோகிக்கப்படும் வரைக்கும் ஓய்வுல இருக்கும் பொருள் ஓய்விலேயே இருக்கும்; இயங்கும் பொருள் சீரான வேகத்துடன் இயங்கும்.
    නිව්ටන්ගේ පළමු නියමය: අසමතුලිත බලයක් නොයෙදෙන තුරු නිශ්චල වස්තුවක් නිශ්චලව ද, ඒකාකාර ප්‍රවේගයෙන් චලනය වන වස්තුවක් එලෙසම ද පවතී.
  • Newton's second law: the acceleration of a body is directly proportional to the unbalanced force applied (F) and inversely proportional to its mass (m).
    நியூற்றனின் இரண்டாவது விதி: ஒரு பொருளுக்கு ஏற்படும் ஆர்முடுகல், பிரயோகிக்கப்படும் சமநிலைப்படுத்தப்படாத விசை (F)-க்கு நேர் விகிதசமம், பொருளோட திணிவு (m)-க்கு நேர்மாறு விகிதசமம்.
    නිව්ටන්ගේ දෙවන නියමය: වස්තුවක ත්වරණය යෙදූ අසමතුලිත බලයට (F) අනුලෝමව සමානුපාතික වන අතර එහි ස්කන්ධයට (m) ප්‍රතිලෝමව සමානුපාතික වේ.
  • Newton's third law: for every action there is an equal and opposite reaction.
    நியூற்றனின் மூன்றாவது விதி: ஒவ்வொரு தாக்கத்துக்கும் சமமும் எதிருமான மறுதாக்கம் உண்டு.
    නිව්ටන්ගේ තුන්වන නියමය: සෑම ක්‍රියාවකටම සමාන හා ප්‍රතිවිරුද්ධ ප්‍රතික්‍රියාවක් ඇත.
  • The weight of an object is the force with which the Earth pulls it towards its centre. It is the force that gives the object the acceleration due to gravity (g): W = m g.
    ஒரு பொருளோட நிறை, புவி அத தன் மையத்த நோக்கி இழுக்கும் விசை. அது பொருளுக்கு புவியீர்ப்பினாலான ஆர்முடுகல் (g)-ஐ கொடுக்க தேவையான விசை: W = m g.
    වස්තුවක බර යනු පෘථිවිය එය එහි කේන්ද්‍රය දෙසට ඇදගන්නා බලයයි. එය වස්තුවට ගුරුත්වජ ත්වරණය (g) ලබා දෙන බලයයි: W = m g.
  • Momentum is mass times velocity: p = m v. Its unit is kg m s⁻¹. It is a vector: it points in the direction of the velocity.
    உந்தம் என்பது திணிவையும் வேகத்தையும் பெருக்கினா கிடைக்குறது: p = m v. அதன் அலகு kg m s⁻¹. அது திசையுள்ள அளவு — வேகத்தோட திசையிலேயே இருக்கும்.
    ගම්‍යතාව යනු ස්කන්ධය සහ ප්‍රවේගය ගුණ කිරීමෙන් ලැබෙන රාශියයි: p = m v. එහි ඒකකය kg m s⁻¹ වේ. එය දෛශික රාශියකි: ප්‍රවේගයේ දිශාවටම පවතී.

Key formulas

Newton's second lawநியூற்றனின் இரண்டாம் விதிනිව්ටන්ගේ දෙවන නියමය

நியூற்றனின் இரண்டாம் விதிනිව්ටන්ගේ දෙවන නියමය

F = m a

  • F = unbalanced forceசமநிலைப்படாத விசைඅසමතුලිත බලය (N)
  • m = massதிணிவுස්කන්ධය (kg)
  • a = accelerationஆர்முடுகல்ත්වරණය (m s⁻²)

A 2 kg trolley at 3 m s⁻²: F = 2 × 3 = 6 N2 kg தள்ளுவண்டி 3 m s⁻² இல்: F = 2 × 3 = 6 N2 kg ට්‍රොලියක් 3 m s⁻² න්: F = 2 × 3 = 6 N

Momentumஉந்தம்ගම්‍යතාව

உந்தம்ගම්‍යතාව

p = m v

  • p = momentumஉந்தம்ගම්‍යතාව (kg m s⁻¹)
  • m = massதிணிவுස්කන්ධය (kg)
  • v = velocityவேகம்ප්‍රවේගය (m s⁻¹)

A 50 kg runner at 4 m s⁻¹: p = 50 × 4 = 200 kg m s⁻¹4 m s⁻¹ இல் ஓடும் 50 kg ஓட்டவீரர்: p = 50 × 4 = 200 kg m s⁻¹4 m s⁻¹ න් දුවන 50 kg ධාවකයෙක්: p = 50 × 4 = 200 kg m s⁻¹

Weightநிறைබර

நிறைබර

W = m g

  • W = weightநிறைබර (N)
  • m = massதிணிவுස්කන්ධය (kg)
  • g = acceleration due to gravityபுவியீர்ப்பினாலான ஆர்முடுகல்ගුරුත්වජ ත්වරණය (10 m s⁻²)

A 5 kg bag: W = 5 × 10 = 50 N5 kg பை: W = 5 × 10 = 50 N5 kg බෑගයක්: W = 5 × 10 = 50 N

A worked example

Worked Example 1 · F = ma · Ch.4, p.94பாட புத்தக உதாரணம் 1 · F = ma · பாடம் 4, ப. 94වැඩ කළ නිදසුන 1 · F = ma · 4 පරි., පි.94

What force is needed to give a 5 kg mass an acceleration of 2 m s-2?
Step 1 1 mark

Write the correct formula: F = ma

Mark for: selecting the correct formula.
Step 2 2 marks

Substitute the values: F = 5 kg × 2 m s-2

= 10 N
Where marks are lost: forgetting the unit N — remember 1 kg m s-2 = 1 N.
Final answer: Force needed = 10 N.
5 kg திணிவுள்ள ஒரு பொருளுக்கு 2 m s⁻² ஆர்முடுகலை வழங்குவதற்குத் தேவையான விசை யாது?
படி 1 1 மதிப்பெண்தொடு, பாரு!

சரியான ஃபார்முலா எழுது: F = ma

மார்க் கிடைக்க: சரியான ஃபார்முலா தேர்ந்தெடுத்ததற்கு.
படி 2 2 மதிப்பெண்தொடு, பாரு!

மதிப்புகளை பொருத்து: F = 5 kg × 2 m s⁻²

= 10 N
மார்க் போகும் இடம்: அலகு N எழுதத் தவறுறது — 1 kg m s⁻² = 1 N என்பதை மறவாதீங்க.
இறுதி பதில்: தேவையான விசை = 10 N.
ස්කන්ධය 5 kg වස්තුවකට 2 m s-2 ත්වරණයක් දීමට අවශ්‍ය බලය කොපමණද?
පියවර 1 ලකුණු 1පෙන්වීමට ස්පර්ශ කරන්න

නිවැරදි සූත්‍රය ලියන්න: F = ma

ලකුණු ලැබෙන්නේ: නිවැරදි සූත්‍රය තෝරා ගැනීමට.
පියවර 2 ලකුණු 2පෙන්වීමට ස්පර්ශ කරන්න

අගයන් ආදේශ කරන්න: F = 5 kg × 2 m s-2

= 10 N
ලකුණු නැති වන්නේ: N ඒකකය අමතක කිරීමෙන් — මතක තබා ගන්න 1 kg m s-2 = 1 N.
අවසාන පිළිතුර: අවශ්‍ය බලය = 10 N.

Try 5 quiz questions

  1. A bus is moving forward at speed and suddenly brakes. Why do standing passengers lurch forward?ஒரு பேருந்து முன்னோக்கி வேகமாக இயங்கிக்கொண்டு திடீரென்று பிரேக் போடுகிறது. நின்றுகொண்டிருக்கும் பயணிகள் ஏன் முன்னோக்கி சாய்கிறார்கள்?

    • A Because the bus pushes them forwardபேருந்து அவர்களை முன்னோக்கி தள்ளுவதால்මොකද බස් රථය ඔවුන් ඉදිරියට තල්ලු කරන නිසා
    • B Because of their body's inertia — it still 'wants' to keep moving forwardஅவர்களின் உடலின் சடத்துவத்தால் — அது இன்னும் முன்னோக்கி இயங்க விரும்புவதால்ඔවුන්ගේ ශරීරයේ අවස්ථිතිය නිසා — එය තවමත් ඉදිරියට චලනය වීමට ‘කැමති’ වේ
    • C Because of Newton's third lawநியூற்றனின் மூன்றாவது விதியால்නිව්ටන්ගේ තුන්වන නියමය නිසා
    • D Because their weight increases suddenlyஅவர்களின் நிறை திடீரென அதிகரிப்பதால்මොකද ඔවුන්ගේ බර හදිසියේ වැඩි වන නිසා
    Show the answer

    Answer: B. Because of their body's inertia — it still 'wants' to keep moving forwardஅவர்களின் உடலின் சடத்துவத்தால் — அது இன்னும் முன்னோக்கி இயங்க விரும்புவதால்ඔවුන්ගේ ශරීරයේ අවස්ථිතිය නිසා — එය තවමත් ඉදිරියට චලනය වීමට ‘කැමති’ වේ

    This is Newton's First Law (inertia) — a moving body keeps moving unless an unbalanced force acts on it. The bus stops, but the passenger's body still 'wants' to keep its forward velocity.இது நியூற்றனின் முதலாவது விதி (சடத்துவம்) — சமநிலைப்படுத்தப்படாத விசை இல்லாத வரை இயங்கும் பொருள் இயங்கிக்கொண்டே இருக்கும். பேருந்து நிற்கிறது, ஆனால் பயணியின் உடல் இன்னும் முன்னோக்கிய வேகத்தை வைத்திருக்க விரும்புகிறது.මෙය නිව්ටන්ගේ පළමු නියමයයි (අවස්ථිතිය) — අසමතුලිත බලයක් නොයෙදෙන තුරු චලනය වන වස්තුවක් චලනය වේ. බස් රථය නතර වේ, නමුත් මගියාගේ ශරීරය තවමත් ඉදිරි ප්‍රවේගය රඳවා ගැනීමට ‘කැමති’ වේ.

  2. A 4 kg object accelerates at 3 m s⁻² when a force is applied. What is that force?4 kg திணிவுள்ள ஒரு பொருள் ஒரு விசை பிரயோகிக்கும்போது 3 m s⁻² ஆர்முடுகலைப் பெறுகிறது. அந்த விசை யாது?

    • A 7 N7 N
    • B 1.33 N1.33 N
    • C 12 N12 N
    • D 4 N4 N
    Show the answer

    Answer: C. 12 N12 N

    F = ma = 4 kg × 3 m s⁻² = 12 N.F = ma = 4 kg × 3 m s⁻² = 12 N.

  3. A swimmer pushes water backward with their hands. What pushes the swimmer forward?ஒரு நீச்சல் வீரர் தன் கைகளால் தண்ணீரை பின்நோக்கி தள்ளுகிறார். நீச்சல் வீரரை முன்னோக்கி தள்ளுவது எது?

    • A The swimmer's own muscles aloneநீச்சல் வீரரின் தசைகள் மட்டும்පිහිනන්නාගේ ම මාංශ පේශි පමණක්
    • B The reaction force from the water, pushing forwardதண்ணீரிலிருந்து வரும் மறுதாக்க விசை, முன்னோக்கி தள்ளுகிறதுජලයෙන් ලැබෙන, ඉදිරියට තල්ලු කරන ප්‍රතික්‍රියා බලය
    • C Gravityபுவியீர்ப்புගුරුත්වය
    • D There is no forward force — the swimmer glides on momentum aloneமுன்னோக்கிய விசை எதுவும் இல்லை — நீச்சல் வீரர் உந்தத்தால் மட்டும் மிதக்கிறார்ඉදිරියට බලයක් නැත — පිහිනන්නා ගම්‍යතාවෙන් පමණක් ලිස්සා යයි
    Show the answer

    Answer: B. The reaction force from the water, pushing forwardதண்ணீரிலிருந்து வரும் மறுதாக்க விசை, முன்னோக்கி தள்ளுகிறதுජලයෙන් ලැබෙන, ඉදිරියට තල්ලු කරන ප්‍රතික්‍රියා බලය

    This is Newton's Third Law — the swimmer's hands push water backward (action), and the water pushes the swimmer forward with an equal and opposite reaction force.இது நியூற்றனின் மூன்றாவது விதி — நீச்சல் வீரரின் கைகள் தண்ணீரைப் பின்நோக்கி தள்ளுகின்றன (தாக்கம்), தண்ணீரும் நீச்சல் வீரரை சமமான, எதிரான மறுதாக்க விசையால் முன்நோக்கித் தள்ளுகிறது.මෙය නිව්ටන්ගේ තුන්වන නියමයයි — පිහිනන්නාගේ අත් ජලය පසුපසට තල්ලු කරයි (ක්‍රියාව), ජලය පිහිනන්නා ඉදිරියට සමාන හා ප්‍රතිවිරුද්ධ ප්‍රතික්‍රියා බලයකින් තල්ලු කරයි.

  4. A 2 kg object moves at 3 m s⁻¹. What is its momentum?2 kg திணிவுள்ள ஒரு பொருள் 3 m s⁻¹ வேகத்தில் இயங்குகிறது. அதன் உந்தம் யாது?

    • A 1.5 kg m s⁻¹1.5 kg m s⁻¹
    • B 5 kg m s⁻¹5 kg m s⁻¹
    • C 6 kg m s⁻¹6 kg m s⁻¹
    • D 9 kg m s⁻¹9 kg m s⁻¹
    Show the answer

    Answer: C. 6 kg m s⁻¹6 kg m s⁻¹

    momentum = mv = 2 kg × 3 m s⁻¹ = 6 kg m s⁻¹.உந்தம் = mv = 2 kg × 3 m s⁻¹ = 6 kg m s⁻¹.ගම්‍යතාව = mv = 2 kg × 3 m s⁻¹ = 6 kg m s⁻¹.

  5. An astronaut has a mass of 80 kg. On the Moon, where gravity is 1/6 of Earth's, what happens to their mass and weight?ஒரு விண்வெளி வீரரின் திணிவு 80 kg. நிலவில், ஈர்ப்பு புவியில் இருப்பதில் 1/6 மட்டுமே இருக்கும். அவருடைய திணிவும் நிறையும் என்ன ஆகும்?

    • A Both mass and weight stay the sameதிணிவும் நிறையும் ரெண்டும் மாறாதுස්කන්ධය සහ බර දෙක ම එලෙසම පවතී
    • B Mass stays 80 kg, weight becomes 1/6 of what it was on Earthதிணிவு 80 kg ஆகவே இருக்கும், நிறை மட்டும் புவியில் இருந்ததில் 1/6 ஆகும்ස්කන්ධය 80 kg ලෙසම පවතී, බර පෘථිවියේ තිබූ අගයෙන් 1/6 ක් වේ
    • C Mass becomes 1/6, weight stays the sameதிணிவு 1/6 ஆகும், நிறை மாறாதுස්කන්ධය 1/6 ක් වේ, බර එලෙසම පවතී
    • D Both mass and weight become 1/6திணிவும் நிறையும் ரெண்டுமே 1/6 ஆகும்ස්කන්ධය සහ බර දෙක ම 1/6 ක් වේ
    Show the answer

    Answer: B. Mass stays 80 kg, weight becomes 1/6 of what it was on Earthதிணிவு 80 kg ஆகவே இருக்கும், நிறை மட்டும் புவியில் இருந்ததில் 1/6 ஆகும்ස්කන්ධය 80 kg ලෙසම පවතී, බර පෘථිවියේ තිබූ අගයෙන් 1/6 ක් වේ

    Mass is the amount of matter — it never changes with location. Weight depends on gravity (W = mg), so on the Moon (1/6 the gravity), weight becomes 1/6 of its Earth value.திணிவு என்பது சடப்பொருளின் அளவு — இடத்தால் ஒருபோதும் மாறாது. நிறை ஈர்ப்பைச் சார்ந்தது (W = mg), அதனால் நிலவில் (1/6 ஈர்ப்பு) நிறை புவியில் இருந்ததில் 1/6 ஆகிவிடும்.ස්කන්ධය යනු ද්‍රව්‍ය ප්‍රමාණයයි — ස්ථානය අනුව එය කිසි විටෙක වෙනස් නොවේ. බර රඳා පවතින්නේ ගුරුත්වය මත ය (W = mg), එබැවින් සඳේදී (ගුරුත්වය 1/6) බර එහි පෘථිවි අගයෙන් 1/6 ක් වේ.

In Tamil and Sinhala · தமிழில் · සිංහලෙන්

Every STEM Cloud lesson is in Tamil, English and Sinhala. The chapter's words, as the lesson uses them:

நியூற்றனின் முதலாவது விதி: சமநிலைப்படுத்தப்படாத விசை பிரயோகிக்கப்படும் வரைக்கும் ஓய்வுல இருக்கும் பொருள் ஓய்விலேயே இருக்கும்; இயங்கும் பொருள் சீரான வேகத்துடன் இயங்கும்.

නිව්ටන්ගේ පළමු නියමය: අසමතුලිත බලයක් නොයෙදෙන තුරු නිශ්චල වස්තුවක් නිශ්චලව ද, ඒකාකාර ප්‍රවේගයෙන් චලනය වන වස්තුවක් එලෙසම ද පවතී.

  • Force · விசை · බලය
  • Unbalanced force · சமநிலைப்படுத்தப்படாத விசை · අසමතුලිත බලය
  • Inertia · சடத்துவம் · අවස්ථිතිය
  • Uniform acceleration · சீரான ஆர்முடுகல் · ඒකාකාර ත්වරණය
  • Uniform velocity · சீரான வேகம் · ඒකාකාර ප්‍රවේගය
  • Mass · திணிவு · ස්කන්ධය
  • Weight · நிறை · බර
  • Acceleration · ஆர்முடுகல் · ත්වරණය
  • Deceleration · அமர்முடுகல் · මන්දනය
  • Action · தாக்கம் · ක්‍රියාව
  • Reaction · மறுதாக்கம் · ප්‍රතික්‍රියාව
  • Momentum · உந்தம் · ගම්‍යතාව

In the full lesson

The full Newton's Laws of Motion lesson walks through every step: the cartoon animation, the notes, all 5 worked examples, the virtual lab, the games and all 5 quiz questions. It opens with an account.

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Questions about Newton's Laws of Motion

Is Newton's Laws of Motion in the G.C.E. O/L Physics syllabus?

Yes. Newton's Laws of Motion is a Grade 10 unit of G.C.E. Ordinary Level Physics in Sri Lanka, and STEM Cloud teaches it in the same order as the course map.

What are the key points of Newton's Laws of Motion?

Newton's first law: a body stays at rest, or keeps moving at uniform velocity, until an unbalanced force acts on it. Newton's second law: the acceleration of a body is directly proportional to the unbalanced force applied (F) and inversely proportional to its mass (m). Newton's third law: for every action there is an equal and opposite reaction.

What are the common mistakes in Newton's Laws of Motion?

Mass ≠ Weight. Everyday speech saying "weight is 60 kg" is technically wrong (kg is the unit of mass) — correctly: "mass is 60 kg," "weight is 600 N." Don't mix up the units (kg vs N) in an exam. All three values in F = ma need the right units — mass always in kg (divide by 1000 if given in grams!), acceleration in m s-2, and force comes out in N. Action and reaction never cancel on one object. They act on two different objects — don't wrongly assume "two opposite forces on the same object" and conclude "so it won't move.". Momentum is a vector quantity — because velocity has direction, momentum does too. If direction reverses, the sign of momentum reverses too (e.g. momentum going up is positive, coming down is negative).

Can I study Newton's Laws of Motion in Tamil or Sinhala?

Yes. Every STEM Cloud lesson is in Tamil, English and Sinhala, and you can switch the language at any time from the lesson header.

How do I get the full Newton's Laws of Motion lesson?

Sign up on the sign-up page, or message the admin on WhatsApp at 077 676 8865. You can try a free lesson first: Motion in a Straight Line.