[{"_1":2,"_548":-5,"_549":-5},"loaderData",{"_3":-5,"_4":-5,"_5":6},"routes/i18nLayout","routes/appGuard","routes/sharingView",{"_7":8,"_9":10},"kind","presentation","data",{"_11":12,"_13":14,"_15":16,"_17":18,"_19":20,"_546":547},"needPin",false,"chatId","87890c70-c700-40fe-8f83-93ff5304ef68","presentationId","6407e273-2ac0-487d-a3dd-b02afd6bc9a7","title","Work, Energy, and Simple Machines","slides",[21,61,76,93,110,127,142,159,174,188,204,220,252,269,283,299,314,330,349,374,388,404,419,433,448,464,478,496,510,531],{"_22":23,"_24":25,"_26":27,"_28":29,"_30":12,"_31":32,"_33":34,"_37":38,"_48":49,"_50":51,"_52":53,"_54":55,"_56":57,"_58":59,"_60":12},"slide",1,"outlineId","51be91d4-a848-4682-a566-67ff1dbafa65","brief","# Work, Energy, and Simple Machines\n## Grade 9 Physics Curriculum Presentation\n\n- Credit Tag: Made by Shreyash Bonde\n- Topic: Fundamental concepts of force, energy transformations, and simple mechanisms\n\n[footnote:] Audio Note: Welcome students to Chapter 7 on Work, Energy, and Simple Machines!","slideType","cover","isInfographic","infographicType","structure","slideLabel",{"_17":18,"_35":36},"shortSummary","Cover Slide","imageRefs",[39],{"_40":41,"_42":43,"_44":45,"_46":47},"source","existing","imageId","ac662175-1ab9-4222-a71b-56631ebc7cd3","imageType","photo","description","An illustration of children playing on a playground slide structure outdoors.","chartRefs",[],"tableRefs",[],"visualRefs",[],"chunkRefs",[],"previewUrl","https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/1/9e96f91b-cc94-47da-a262-7cd4f2e6b95f.webp","gate","watermark","previewLocked",{"_22":62,"_24":63,"_26":64,"_28":65,"_30":12,"_31":32,"_33":66,"_37":69,"_48":71,"_50":72,"_52":73,"_54":74,"_56":75,"_58":59,"_60":12},2,"40a2e7ba-f839-4b5f-8c4e-929cc01c06c1","# Presentation Roadmap\n## Chapter 7 Overview\n\n1. Work Done by a Constant Force\n2. The Work-Energy Theorem and Forms of Energy\n3. Mechanical Energy (Kinetic and Potential)\n4. Power and Rate of Energy Transfer\n5. Simple Machines and Mechanical Advantage\n\n[footnote:] Audio Note: Today we will cover five key sections in original textbook order.","agenda",{"_17":67,"_35":68},"Presentation Roadmap","Chapter 7 Overview",[70],{"_40":41,"_42":43,"_44":45,"_46":47},[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/2/46d3dd73-3afe-41f7-a834-b71f5e045fcc.webp",{"_22":77,"_24":78,"_26":79,"_28":80,"_30":12,"_31":32,"_33":81,"_37":84,"_48":88,"_50":89,"_52":90,"_54":91,"_56":92,"_58":59,"_60":12},3,"494caa43-4c69-47e3-9788-1ae72d644ec2","# Section 1: Work Done by a Constant Force\n\n[headnote:] Chapter 7.1\n\nUnderstanding how applied forces cause displacement in scientific terms.","section_divider",{"_17":82,"_35":83},"Work Done by a Constant Force","Section 1",[85],{"_40":41,"_42":86,"_44":45,"_46":87},"39a692a3-c15f-4be6-824f-e803f19f809f","An illustration of a man pushing an elderly woman in a wheelchair.",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/3/c0ce250d-b628-41f0-a76c-00be5ad1c1d8.webp",{"_22":94,"_24":95,"_26":96,"_28":97,"_30":12,"_31":98,"_33":99,"_37":102,"_48":105,"_50":106,"_52":107,"_54":108,"_56":109,"_58":59,"_60":12},4,"c892eb59-2f14-4332-b38d-3c41f5bfbe40","# What is Work in Physics?\n## Everyday Language vs. Scientific Definition\n\n### Everyday Understanding\n- Any mental or physical exertion that leads to fatigue (e.g. holding a heavy bag, pushing a wall).\n\n### Scientific Definition\n- Work is done ONLY when a force acts on an object AND causes displacement in the direction of the force.\n- Lifting 3 identical 5 kg bags requires 3 times more force and does 3 times more work than lifting 1 bag.\n\n[footnote:] Source: Grade 9 Science Textbook, Chapter 7.1","explanation","comparison",{"_17":100,"_35":101},"What is Work in Physics?","Definition of work",[103],{"_40":41,"_42":86,"_44":45,"_46":104},"A man pushing an elderly woman in a wheelchair",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/4/0b3262a9-35b8-4137-a6b6-d924e77ba01a.webp",{"_22":111,"_24":112,"_26":113,"_28":114,"_30":12,"_31":32,"_33":115,"_37":118,"_48":122,"_50":123,"_52":124,"_54":125,"_56":126,"_58":59,"_60":12},5,"643d040d-7cbf-4ae8-b635-304b92ec0c4c","# The Mathematical Formula for Work\n\n> Work Done (W) = Force (F) × Displacement (s)\n\n### Unit Breakdown\n- SI Unit of Work: Joule (J)\n- 1 Joule = 1 Newton × 1 Metre (1 J = 1 N · m)\n- Scalar Quantity: Work has magnitude but no direction.\n\n[footnote:] Audio Note: Remember that work is a scalar quantity even though force and displacement are vectors.","big_statement",{"_17":116,"_35":117},"Mathematical Formula for Work","Formula and units",[119],{"_40":41,"_42":120,"_44":45,"_46":121},"ffb7dabc-26f9-489f-bb83-aff4071241a4","A goalkeeper diving to catch a soccer ball near the goal post on a grass field.",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/5/1a2be73c-1fea-436e-832d-0802e18ead9b.webp",{"_22":128,"_24":129,"_26":130,"_28":98,"_30":12,"_31":98,"_33":131,"_37":134,"_48":137,"_50":138,"_52":139,"_54":140,"_56":141,"_58":59,"_60":12},6,"d1fc3546-c5d3-4e8a-966b-a76a442b8d41","# Direction Matters: Positive vs. Negative Work\n\n### Positive Work\n- Force and displacement are in the SAME direction.\n- Example: Pushing a wheelchair forward accelerates it.\n- Energy is transferred TO the object.\n\n### Negative Work\n- Force and displacement are in OPPOSITE directions.\n- Example: A goalkeeper applying force to stop a moving football.\n- Energy is removed FROM the object.",{"_17":132,"_35":133},"Positive vs. Negative Work","Comparison",[135,136],{"_40":41,"_42":86,"_44":45,"_46":87},{"_40":41,"_42":120,"_44":45,"_46":121},[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/6/6b5f2f72-f48d-45f4-9a22-b06ede674546.webp",{"_22":143,"_24":144,"_26":145,"_28":146,"_30":12,"_31":32,"_33":147,"_37":150,"_48":154,"_50":155,"_52":156,"_54":157,"_56":158,"_58":59,"_60":12},7,"5bef6140-44b2-48df-bc83-95ec37db5b25","# When is Scientific Work Equal to Zero?\n## Two Key Scenarios Where Zero Work is Performed\n\n### Case 1: Zero Displacement (s = 0)\n- Pushing hard against a rigid brick wall results in no displacement.\n- Even though your muscles contract and expend chemical energy, scientific work done on the wall is zero.\n\n### Case 2: Perpendicular Force (Force ⊥ Displacement)\n- Carrying a box vertically while walking horizontally.\n- Force is upward (against gravity), while motion is horizontal (90° angle).\n- No displacement occurs in the direction of the applied force.","problem",{"_17":148,"_35":149},"When is Scientific Work Equal to Zero?","Zero Work Scenarios",[151],{"_40":41,"_42":152,"_44":45,"_46":153},"76457bbd-0254-45dc-b62a-d358b8af04e8","An illustration sequence of a person walking while carrying a cardboard box.",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/7/e981fe34-2eaa-4001-9dbd-c65db3618256.webp",{"_22":160,"_24":161,"_26":162,"_28":163,"_30":12,"_31":32,"_33":164,"_37":167,"_48":169,"_50":170,"_52":171,"_54":172,"_56":173,"_58":59,"_60":12},8,"0ecbca96-d4f6-402f-9696-6dd84505036f","# Example Calculation: Stopping a Football\n\n> Work done by goalkeeper = 200 N × (-0.15 m) = -30 Joules\n\n### Step-by-Step Numerical Analysis\n- Given Force applied by goalkeeper: F = 200 N (opposite to ball motion)\n- Given Backward displacement of hands: s = -0.15 m (15 cm backward)\n- Calculation: W = F × s = 200 N × (-0.15 m) = -30 J\n- Conclusion: The goalkeeper does negative work on the ball, removing 30 J of energy to bring it to rest.","case_study",{"_17":165,"_35":166},"Example Calculation: Stopping a Football","Case study",[168],{"_40":41,"_42":120,"_44":45,"_46":121},[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/8/d2ad088c-af78-4737-9d8f-615949fb4ba1.webp",{"_22":175,"_24":176,"_26":177,"_28":80,"_30":12,"_31":32,"_33":178,"_37":181,"_48":183,"_50":184,"_52":185,"_54":186,"_56":187,"_58":59,"_60":12},9,"2c13db57-3cfb-4323-bcd5-4f4ae4994201","# Section 2: The Work-Energy Theorem & Forms of Energy\n\n[headnote:] Chapter 7.2 & 7.3\n\nExploring how work transfers energy and examining the various forms of energy in nature.",{"_17":179,"_35":180},"Section 2: Work-Energy Theorem","Section Divider",[182],{"_40":41,"_42":43,"_44":45,"_46":47},[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/9/ed52e641-3da0-4659-959a-6472fbe9177a.webp",{"_22":189,"_24":190,"_26":191,"_28":97,"_30":12,"_31":32,"_33":192,"_37":195,"_48":199,"_50":200,"_52":201,"_54":202,"_56":203,"_58":59,"_60":12},10,"e829d6cf-6c05-4d7d-8208-d19d771ee701","# The Relationship Between Work and Energy\n## Energy as the Capacity to Do Work\n\n### Key Principles\n- Energy is defined as the capacity of an object to perform work.\n- Doing positive work on an object imparts energy to it.\n- An object that possesses energy can subsequently exert force on another object, doing work and transferring energy.\n- Example: A fielder throws a ball (does work on it); the moving ball possesses energy and knocks down the wickets.",{"_17":193,"_35":194},"Work and Energy Relationship","Energy principles",[196],{"_40":41,"_42":197,"_44":45,"_46":198},"2b29223f-acb0-48d5-bcb1-84bef6fb7d4f","A cricketer in blue sportswear throwing a red ball in a fielding stance.",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/10/41d2de18-856c-4fe0-a58c-35989d56fcec.webp",{"_22":205,"_24":206,"_26":207,"_28":114,"_30":12,"_31":32,"_33":208,"_37":211,"_48":215,"_50":216,"_52":217,"_54":218,"_56":219,"_58":59,"_60":12},11,"a71a4434-c1c8-4625-865c-7abd189de10c","# The Work-Energy Theorem\n\n> Work done on an object = Net change in its energy\n\n### Key Highlights\n- Shared Unit: Both Work and Energy are measured in Joules (J).\n- Named after scientist James Prescott Joule, who established the link between mechanical and thermal energy.\n- Applies to single objects, composite systems, and both constant or variable forces.",{"_17":209,"_35":210},"The Work-Energy Theorem","Theorem overview",[212],{"_40":41,"_42":213,"_44":45,"_46":214},"481d5935-604a-4242-ab78-4045c1bcb3a5","Physics concept diagram illustrating the work-energy theorem",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/11/06433379-c76b-4b7d-9afb-2dace6f0f653.webp",{"_22":221,"_24":222,"_26":223,"_28":224,"_30":12,"_31":32,"_33":225,"_37":228,"_48":238,"_50":239,"_52":249,"_54":250,"_56":251,"_58":59,"_60":12},12,"ecbd5010-daf9-40f2-bfd6-49d823b247a1","# Diverse Forms of Energy in Nature\n## Energy exists in many forms and readily converts from one type to another\n- Thermal energy makes things warm or hot\n- Light energy allows us to see our surroundings\n- Electrical energy powers our daily devices\n[footnote:] Source: Chapter 2, Work, Energy, and Simple Machines","gallery",{"_17":226,"_35":227},"Diverse Forms of Energy","Energy forms",[229,232,235],{"_40":41,"_42":230,"_44":45,"_46":231},"beb28ef9-ed75-4078-b914-078aab30296a","glowing electric lightbulb representing electrical and light energy",{"_40":41,"_42":233,"_44":45,"_46":234},"24b2f86b-2913-450b-8ba1-917c30babbb5","burning campfire close up showing thermal and light energy",{"_40":41,"_42":236,"_44":45,"_46":237},"0badb76c-745a-445d-8332-6de373d84b6a","solar panels grid underneath bright sunny sky renewable clean energy",[],[240],{"_241":242,"_243":244,"_245":246,"_247":248},"tableId","a35eab25-6f4d-4f57-870a-1032079c2c15","tableHtml","

\| Mechanical energy Thermal energy
Energy due to motion Energy that
or position of objects makes things
warm or hot
Light energy Sound energy
Energy that Energy of
allows us to vibrations of air or
see other molecules
Electrical energy Nuclear energy
Energy related to Energy stored in
position or motion the nuclei of atoms
of charges
Chemical energy
Energy stored in fuels and food
in the form of chemical bonds
between atoms
as shown in Fig. 7.10. It is possible to change energy from one
Mechanical energy Therm
form to another. For example, electrical energy is converted
Energy due to motion Ener
into light energy in a bulb, and into thermal energy or position of objects make
Grade 7 of the water in an electric water heater. The chemical warm
Curiosity
Chapter 3 energy in the food we eat powers our muscles and
gets converted into mechanical energy. Similarly,
Grade 6
Curiosity a ringing bell converts mechanical energy into
Chapter 3
sound energy.
Light energy Sound
Among these, we will now look more closely at mechanical
Energy that Ene
energy, since it is directly connected to the forces and motions allows us to vibratio
see other
you studied earlier.
7.4 Mechanical Energy
Mechanical energy is the energy that an object possesses due
to its motion or position. Let us try to quantify mechanical
Electrical energy Nuclea
energy by using the concept of work.
Energy related to Energy
position or motion the nucl
7.4.1 Kinetic energy
of charges
The energy possessed by an object due to its motion is called
kinetic energy. All moving objects possess kinetic energy,
such as a moving bicycle or a rolling ball.
How much is the energy possessed by an object by virtue of
its motion? It is common to define an object that does not move Chemical energy
to have zero kinetic energy. Consider an object that starts from Energy stored in fuels a
in the form of chemical
rest and acquires a certain velocity under the influence of a
between atoms
force F (Fig. 7.11). Then by the work-energy theorem, the work
done by the force will equal to the energy gained by the object, Fig. 7.10: Different forms o
which is the kinetic energy of the object in this case.
Initial velocity = 0 Final velocity = v
Initial Kinetic energy = 0 Final Kinetic energy = K
Work done by force
W = F × s
F	Mechanical energy Therm
Energy due to motion Ener
or position of objects make
warm
Light energy Sound
Energy that Ene
allows us to vibratio
see other
Electrical energy Nuclea
Energy related to Energy
position or motion the nucl
of charges
Chemical energy
Energy stored in fuels a
in the form of chemical
between atoms

","summary","| Mechanical energy Thermal energy","requestId","4b1e5b8f-2cd0-4b8d-bb60-8d6710969276",[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/12/a4c5e76d-95d6-4611-b892-ceb45873d5e1.webp",{"_22":253,"_24":254,"_26":255,"_28":256,"_30":12,"_31":32,"_33":257,"_37":260,"_48":264,"_50":265,"_52":266,"_54":267,"_56":268,"_58":59,"_60":12},13,"ce62da9b-11d6-46c7-9eb3-a8ce2b70a224","# Concept Check: Carrom Ball Collisions\n## When a striker hits a white coin, which in turn strikes a black coin:\n\n- Striker does positive work on the white coin, increasing its energy\n- White coin does negative work on the striker, slowing it down\n- White coin does positive work on the black coin, setting it in motion\n- All of the above energy transfers occur simultaneously according to Newton's 3rd Law","quiz",{"_17":258,"_35":259},"Concept Check: Carrom Ball Collisions","Quiz",[261],{"_40":41,"_42":262,"_44":45,"_46":263},"9e915e0b-fd5e-4a93-acea-3ac88ba162bd","A top-down view of a carrom board with game pieces arranged on the playing surface.",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/13/1041eeea-3d12-4db4-a611-6fd6b10301af.webp",{"_22":270,"_24":271,"_26":272,"_28":80,"_30":12,"_31":32,"_33":273,"_37":276,"_48":278,"_50":279,"_52":280,"_54":281,"_56":282,"_58":59,"_60":12},14,"0524e0c8-4dcd-43ca-ab69-bc4c201c1a8f","# Section 3: Mechanical Energy\n\n[headnote:] Chapter 7.4\n\nKinetic energy, Potential energy, and the Law of Conservation of Mechanical Energy.",{"_17":274,"_35":275},"Section 3: Mechanical Energy","Section divider",[277],{"_40":41,"_42":43,"_44":45,"_46":47},[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/14/38b6716f-e4ab-4dc5-983a-6ea30095ed5c.webp",{"_22":284,"_24":285,"_26":286,"_28":97,"_30":12,"_31":32,"_33":287,"_37":290,"_48":294,"_50":295,"_52":296,"_54":297,"_56":298,"_58":59,"_60":12},15,"ec85ff59-537b-4cb0-8ce7-24de86b89644","# Kinetic Energy: Energy of Motion\n## Deriving Kinetic Energy from Kinematic Equations\n\n### Mathematical Derivation\n- From third equation of motion: v² = u² + 2as ⇒ s = (v² - u²) / (2a)\n- Work done: W = F × s = (ma) × [(v² - u²) / (2a)] = ½ m(v² - u²)\n- If object starts from rest (u = 0), Kinetic Energy (K) = ½ m v²\n\n### Key Characteristics\n- Depends on mass (m) and square of velocity (v²).\n- Doubling velocity quadruples the kinetic energy (2² = 4 times).",{"_17":288,"_35":289},"Kinetic Energy: Energy of Motion","Derivation",[291],{"_40":41,"_42":292,"_44":45,"_46":293},"abcf6576-105c-4d8e-a3b0-56d237cb4e52","Side profile view of a blue compact car with a driver inside",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/15/85f1489e-dadc-4eb9-aad0-5823f1058f9e.webp",{"_22":300,"_24":301,"_26":302,"_28":163,"_30":12,"_31":32,"_33":303,"_37":306,"_48":309,"_50":310,"_52":311,"_54":312,"_56":313,"_58":59,"_60":12},16,"4f9c02ef-cc1c-4a4d-946e-db598c8b07fd","# Calculation: Fast-Bowled Cricket Ball\n\n> Kinetic Energy K = ½ × 0.2 kg × (43 m/s)² = 184.9 Joules\n\n### Problem Parameters\n- Mass of cricket ball: m = 0.2 kg\n- Delivery speed: v = 154.8 km/h = 43 m/s\n- Formula applied: K = ½ m v²\n- Substitution: K = ½ × (0.2 kg) × (43 m/s)² = 184.9 J\n- Insight: High kinetic energy makes stopping fast-moving objects difficult.",{"_17":304,"_35":305},"Calculation: Fast-Bowled Cricket Ball","Case Study",[307],{"_40":41,"_42":197,"_44":45,"_46":308},"An illustration of a cricketer in blue sportswear throwing a red ball in a fielding stance.",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/16/c4533122-22b5-4edb-b34e-1577daf164a0.webp",{"_22":315,"_24":316,"_26":317,"_28":97,"_30":12,"_31":32,"_33":318,"_37":321,"_48":325,"_50":326,"_52":327,"_54":328,"_56":329,"_58":59,"_60":12},17,"c3fe80a1-7f86-4fb6-9a83-509ce1c86072","# Potential Energy: Stored Energy\n## Energy Stored Due to Configuration or Position\n\n### Elastic Potential Energy\n- Energy stored in a deformed object (e.g. stretched slingshot, compressed spring, bent archery bow).\n- Work done to deform the spring is stored as potential energy until released.\n\n### Gravitational Potential Energy\n- Energy stored in a system when objects are separated against gravitational force.\n- Example: Lifting a stone or flowerpot to a height above the ground.",{"_17":319,"_35":320},"Potential Energy: Stored Energy","Explanation",[322],{"_40":41,"_42":323,"_44":45,"_46":324},"c7505a18-0d99-489c-ae29-193be3fcd868","A close-up view of flower pots placed on the brick balcony ledges of a building.",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/17/3ecb74dc-283c-4f42-ae42-cb4f5aa213d0.webp",{"_22":331,"_24":332,"_26":333,"_28":97,"_30":12,"_31":32,"_33":334,"_37":337,"_48":339,"_50":340,"_52":346,"_54":347,"_56":348,"_58":59,"_60":12},18,"057be2b0-0e61-4c32-acf8-eaac63c60c50","# Gravitational Potential Energy Formula\n## Quantifying Potential Energy Near Earth's Surface\n\n### Mathematical Formulation\n- Force needed to lift mass 'm' slowly: F = mg\n- Displacement through vertical height 'h': s = h\n- Work done W = F × s = mg × h = mgh\n- Potential Energy: U = mgh\n\n### Activity 7.1 Observation\n- Dropping a heavy ball into sand from higher altitudes produces deeper depressions.\n- Deeper depression confirms higher potential energy stored at greater heights.",{"_17":335,"_35":336},"Gravitational Potential Energy Formula","Formula and Activity",[338],{"_40":41,"_42":43,"_44":45,"_46":47},[],[341],{"_241":342,"_243":343,"_245":344,"_247":345},"d708f1af-7036-4a7d-97a6-f6f98338375d","

\| Gravitational
Force

","| Gravitational","32dff999-c817-4956-b779-ab020ac57dd0",[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/18/eba74c22-6799-4277-85a7-87bb29d7f64e.webp",{"_22":350,"_24":351,"_26":352,"_28":353,"_30":12,"_31":32,"_33":354,"_37":357,"_48":359,"_50":360,"_52":371,"_54":372,"_56":373,"_58":59,"_60":12},19,"2f57cc58-45d0-46ec-82ea-10e299098813","# Conservation of Mechanical Energy\n## Total Mechanical Energy = Kinetic Energy + Potential Energy = Constant\n\n### Top Point A (Height h)\nInitial velocity u = 0. Potential Energy = mgh, Kinetic Energy = 0. Total ME = mgh.\n\n### Mid-Fall Point B (Height h')\nFalling for time t with velocity v = gt. PE = mgh', KE = ½mg²t². Total ME = mgh.\n\n### Bottom Point C (Ground Impact)\nHeight h = 0. Potential Energy = 0, Kinetic Energy = mgh. Total ME = mgh.","timeline",{"_17":355,"_35":356},"Conservation of Mechanical Energy","Energy constancy",[358],{"_40":41,"_42":43,"_44":45,"_46":47},[],[361,366],{"_241":362,"_243":363,"_245":364,"_247":365},"cc5de31a-9f0c-41c7-884e-e59e802d0f7b","

h	′

","h, ′","4b54981b-8a1a-4aa2-8d75-cb2b1f717a94",{"_241":367,"_243":368,"_245":369,"_247":370},"7823f562-c9bd-4d85-8cb1-e82e200f827b","

(h –	h ′)

","(h –, h ′)","4028ddb2-f3fc-49d8-91c2-430ccae440ec",[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/19/e9253834-314e-4f57-a71e-0fed6e10d4c9.webp",{"_22":375,"_24":376,"_26":377,"_28":146,"_30":12,"_31":32,"_33":378,"_37":381,"_48":383,"_50":384,"_52":385,"_54":386,"_56":387,"_58":59,"_60":12},20,"44c740c6-6d8c-4e61-b19e-e303a14bfd1f","# Real-World Pendulum & Energy Losses\n## Ideal Conservation vs. Dissipative Forces\n\n### Ideal Oscillating Pendulum\n- At extreme points P & R: Velocity = 0, Height max ⇒ Only Potential Energy.\n- At lowest point Q: Height min, Velocity max ⇒ Only Kinetic Energy.\n\n### Real-World Friction Effects\n- In real life, mechanical energy is gradually dissipated as thermal and acoustic energy due to air resistance and pivot friction.\n- Audio Note: Explain that total energy of the universe remains conserved even when mechanical energy decreases.",{"_17":379,"_35":380},"Real-World Pendulum & Energy Losses","Friction & Energy Dissipation",[382],{"_40":41,"_42":43,"_44":45,"_46":47},[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/20/d7744fb7-c49f-457d-b414-cddf7cc08db8.webp",{"_22":389,"_24":390,"_26":391,"_28":80,"_30":12,"_31":32,"_33":392,"_37":395,"_48":399,"_50":400,"_52":401,"_54":402,"_56":403,"_58":59,"_60":12},21,"4617180f-64c4-4924-8a00-a86a3be77a64","# Section 4: Power\n\n[headnote:] Chapter 7.5\n\nThe rate of doing work and energy transfer over time.",{"_17":393,"_35":394},"Section 4: Power","Power overview",[396],{"_40":41,"_42":397,"_44":45,"_46":398},"fa066e69-ef99-4a14-8acb-60e8e20be93a","fighter jet parked on the flight deck",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/21/8f39816a-37b6-49e1-b99b-24a1abab6000.webp",{"_22":405,"_24":406,"_26":407,"_28":97,"_30":12,"_31":32,"_33":408,"_37":411,"_48":414,"_50":415,"_52":416,"_54":417,"_56":418,"_58":59,"_60":12},22,"e577b5e1-387d-4530-993d-616ef1dac26d","# What is Power?\n## Rate of Doing Work\n\n### Definition and Formula\n- Power is defined as the rate at which work is performed or energy is converted.\n- Average Power P = Work Done (W) / Time Taken (t)\n- SI Unit: Watt (W), named after James Watt.\n- 1 Watt = 1 Joule per second (1 W = 1 J/s)\n\n### Concept Intuition\n- Running up stairs in 1 minute requires more power than walking slowly up the same stairs in 5 minutes, even though total work done is identical.",{"_17":409,"_35":410},"What is Power?","Rate of Doing Work",[412],{"_40":41,"_42":43,"_44":45,"_46":413},"Children playing on a playground slide",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/22/29ad1b08-d8da-4850-8564-0444350c141f.webp",{"_22":420,"_24":421,"_26":422,"_28":98,"_30":12,"_31":98,"_33":423,"_37":425,"_48":428,"_50":429,"_52":430,"_54":431,"_56":432,"_58":59,"_60":12},23,"b6e0dee3-9dee-4f83-9859-f5c28c299a9b","# Units of Power: Watt vs. Horsepower\n\n### Watt (SI Unit)\n- Standard metric unit used in scientific and electrical measurements.\n- 1 Watt = 1 Joule per second.\n- Electric bulbs, fans, and electronics rated in Watts (W) or Kilowatts (kW).\n\n### Horsepower (hp)\n- Traditional unit established by James Watt to compare steam engine power to horses.\n- Conversion factor: 1 horsepower (hp) = 746 Watts.\n- Commonly used for automotive engines, water pumps, and industrial motors.",{"_17":424,"_35":133},"Units of Power: Watt vs. Horsepower",[426],{"_40":41,"_42":292,"_44":45,"_46":427},"Side profile view of a blue compact car with a driver inside.",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/23/f6235e63-81bd-4eb4-b10f-09209394be2d.webp",{"_22":434,"_24":435,"_26":436,"_28":163,"_30":12,"_31":32,"_33":437,"_37":440,"_48":443,"_50":444,"_52":445,"_54":446,"_56":447,"_58":59,"_60":12},24,"7a96e128-af69-437d-88af-5f05d8dd8bca","# Power Calculation: Weightlifter Example\n\n> Power P = (75 kg × 10 m/s² × 2 m) / 5 s = 300 Watts\n\n### Calculation Breakdown\n- Given Mass m = 75 kg, Height h = 2 m, Time t = 5 s, g = 10 m/s²\n- Work done W = mgh = 75 kg × 10 m/s² × 2 m = 1500 Joules\n- Power calculation P = W / t = 1500 J / 5 s = 300 W\n- Result: The weightlifter generates 300 Watts of power during the lift.",{"_17":438,"_35":439},"Power Calculation: Weightlifter Example","Weightlifter Case Study",[441],{"_40":41,"_42":397,"_44":45,"_46":442},"A weightlifter lifting heavy weights in a training session",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/24/413d74e9-12f9-47df-849e-2f86b912eca1.webp",{"_22":449,"_24":450,"_26":451,"_28":80,"_30":12,"_31":32,"_33":452,"_37":455,"_48":457,"_50":458,"_52":459,"_54":460,"_56":461,"_58":462,"_60":463},25,"92a6831e-8802-4813-9baf-6afc981de519","# Section 5: Simple Machines\n\n[headnote:] Chapter 7.6\n\nDevices that alter force direction or magnitude to facilitate work.",{"_17":453,"_35":454},"Section 5: Simple Machines","Simple Machines",[456],{"_40":41,"_42":43,"_44":45,"_46":47},[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/25/54a9e9bc-903e-4b85-9182-546592fffbe5.webp","watermark_blur",true,{"_22":465,"_24":466,"_26":467,"_28":97,"_30":12,"_31":32,"_33":468,"_37":471,"_48":473,"_50":474,"_52":475,"_54":476,"_56":477,"_58":462,"_60":463},26,"9cca4f44-983a-4b8f-90d1-cfbd1e7f925e","# Understanding Simple Machines\n## Effort, Load, and Mechanical Advantage\n\n### Core Terms\n- Effort: The input force applied to the machine.\n- Load: The resistance force to be overcome by the machine.\n- Mechanical Advantage (MA): The ratio of Load to Effort (MA = Load / Effort).\n\n### Fundamental Rule\n- Simple machines CANNOT reduce total work required (Energy Conservation).\n- They make work easier by multiplying force magnitude OR changing direction of applied force.",{"_17":469,"_35":470},"Understanding Simple Machines","Core Terms and MA",[472],{"_40":41,"_42":86,"_44":45,"_46":87},[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/26/6a301766-c15c-4cdc-9e47-6485060a92e3.webp",{"_22":479,"_24":480,"_26":481,"_28":97,"_30":12,"_31":32,"_33":482,"_37":485,"_48":491,"_50":492,"_52":493,"_54":494,"_56":495,"_58":462,"_60":463},27,"bc74f1ab-bbba-4f7b-b931-8aa06789573d","# The Pulley System\n## Fixed vs. Movable Pulleys\n\n### Fixed Pulley\n- Wheel with a groove fixed to a rigid support.\n- Does NOT amplify force (Mechanical Advantage = 1).\n- Provides convenience by changing direction of effort (pulling down with gravity is easier than lifting up).\n\n### Movable Pulley\n- Pulley moves along with the load.\n- Doubles input force (Mechanical Advantage = 2), requiring half the effort.",{"_17":483,"_35":484},"The Pulley System","Fixed vs Movable",[486],{"_40":487,"_42":488,"_44":489,"_46":490,"_247":488},"search","aceb108e-6ef5-408d-bbbb-e3c131a0086a","diagram","Physics diagram showing fixed and movable pulley systems with mechanical advantage",[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/27/cad4257d-7f0c-4e84-9edb-e6a9a534a1a0.webp",{"_22":497,"_24":498,"_26":499,"_28":98,"_30":12,"_31":98,"_33":500,"_37":503,"_48":505,"_50":506,"_52":507,"_54":508,"_56":509,"_58":462,"_60":463},28,"24d81258-972e-4244-a18c-ee52450afecd","# Inclined Planes & Ramps\n\n### Vertical Lift\n- Requires applying full force equal to weight (F = mg) directly upward.\n- Distance moved is short (height h).\n\n### Inclined Plane Ramp\n- Allows lifting heavy loads using smaller effort force over a longer ramp distance.\n- Trade-off: Reduced effort force required, but distance travelled increases proportionally.\n- Practical Application: Highway escape ramps filled with gravel to safely decelerate runaway trucks.",{"_17":501,"_35":502},"Inclined Planes & Ramps","Physics of Ramps",[504],{"_40":41,"_42":43,"_44":45,"_46":47},[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/28/8c6bb899-3b30-460e-a842-e143bd91fe2b.webp",{"_22":511,"_24":512,"_26":513,"_28":97,"_30":12,"_31":32,"_33":514,"_37":517,"_48":521,"_50":522,"_52":528,"_54":529,"_56":530,"_58":462,"_60":463},29,"b9c8444b-fdfe-441b-8560-1a53549d6e9e","# The Three Classes of Levers\n## Classification Based on Relative Positions of Fulcrum, Load, and Effort\n- Class I levers feature the fulcrum situated between the load and the effort.\n - Examples include scissors, crowbars, pliers, balance scales, and seesaws.\n- Class II levers position the load between the fulcrum and the effort.\n - Examples include lemon squeezers, wheelbarrows, and bottle openers.\n- Class III levers place the effort between the fulcrum and the load.\n - Examples include tongs, tweezers, brooms, hammers, and oars.\n[footnote:] Many daily machines combine multiple simple machines.",{"_17":515,"_35":516},"Three Classes of Levers","Lever classification",[518],{"_40":41,"_42":519,"_44":489,"_46":520},"877db8e9-a82b-4dce-887a-66276e66b406","Illustration of different classes of levers showing fulcrum, load, and effort positions.",[],[523],{"_241":524,"_243":525,"_245":526,"_247":527},"df4a58f5-66d7-4ae5-9e8d-8e6830b307cc","

\| Levers		\|
\| Class I	Class II	Class III \|
Fulcrum in between Load in between Effort in between
Fulcrum Fulcrum Fulcrum
Load Effort Load Effort Effort Load
Tongs, scissors, crowbar, Lemon squeezer, wheel Tongs, tweezers, broom,
pliers, balance scale, seesaw barrow, bottle opener hammer, oar
Many machines used in daily life are made up of two or more simple
machines. The next time you see a machine, try to identify the simple
machines within them.
In all cases, the conservation of mechanical energy holds. The work
we put in is equal to the useful work done on the load, ignoring friction.
Machines do not create energy, they only help us use it more effectively.
Pause and Ponder Wha
it were po
11. \u0007Why is it easier to open the lid of a can by using
to build a
a spoon as shown in Fig. 7.35?
perpetual
12. \u0007Why do you push an object closer to scissors
motion
fulcrum when you want to cut an object which
machine,
is hard?
once start
13. \u0007Throughout history, many designs of perpetual
could con
Fig. 7.35: Opening the
machines (using wheels, weights or magnets)
lid by using a spoon doing use
have been proposed but none actually work.
work fore			\|
\| Fulcrum in between	Load in between	Effort in between \|
\| Fulcrum
Effort
Load	Fulcrum
Load Effort	Fulcrum
Effort Load \|
\|		\|
\| Tongs, scissors, crowbar,
pliers, balance scale, seesaw	Lemon squeezer, wheel
barrow, bottle opener	Tongs, tweezers, broom,
hammer, oar \|
\|		\|

","| Levers, , |","d28982bf-0f1b-4e90-a136-610d7cec10f6",[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/29/77e87897-cbfb-4fff-aa40-999748c2f973.webp",{"_22":532,"_24":533,"_26":534,"_28":535,"_30":12,"_31":32,"_33":536,"_37":539,"_48":541,"_50":542,"_52":543,"_54":544,"_56":545,"_58":462,"_60":463},30,"e2713b18-17b4-4b8b-8883-3d231e2bbba1","# Summary & Key Takeaways\n\n> Work, Energy, and Power form the foundation of classical mechanics and everyday machines.\n\n- Work Formula: W = F × s (Joule)\n- Work-Energy Theorem: Net Work = Δ Energy\n- Mechanical Energy: ME = ½ m v² + mgh = Constant\n- Power: P = W / t (Watt)\n- Simple Machines: Trade force for distance (MA = Load / Effort)\n\n[footnote:] Educational presentation created by Shreyash Bonde | Grade 9 Physics","closing_cta",{"_17":537,"_35":538},"Summary & Key Takeaways","Conclusion",[540],{"_40":41,"_42":43,"_44":45,"_46":47},[],[],[],[],"https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/slides/30/46cbf423-fa57-45f1-ac87-2ad1e845d4dc.webp","downloadUrl","https://files.wonderslide.com/storage/48/37/3900/chats/87890c70-c700-40fe-8f83-93ff5304ef68/presentations/6407e273-2ac0-487d-a3dd-b02afd6bc9a7/662504f0-4862-4058-b95d-09f2f6a86149.pdf","actionData","errors"]