1. Hooke’s Law & DeformationElastic = returns to shape ✔️Plastic = stays stretched ❌ 2. UnitsForce = NSpring constant (k) = N/mDisplacement (x) = m 3. UsesCar shocks, trampolines, scales, pens, springs in machines 4. Test ItHang spring → add weights → measure stretch → straight line = Hooke’s Law 5. Limits Only works before the material stretches too far 6. Springs in Series & Parallel Series = weaker Parallel = stronger

1. Pressure = Force ÷ Area– More force = more pressure– Bigger area = less pressure 2. Pressure in fluids = ρ × g × h– Increases with depth, density, or gravity(ρ = density, g = gravity, h = depth) 3. Atmospheric Pressure at Sea Level= 101,325 Pa or 1 atm(Caused by air’s weight above us) 4. Hydraulic SystemsUse fluid pressure to move things.Small force on small piston = big force on big piston. 5. Gas Pressure: Ideal Gas Law P=nRTVP = \frac{nRT}{V}P=VnRT​ More gas, higher temperature, or smaller volume = higher pressure. 6. Uses in Engineering– Dams, airplanes, car brakes, pipelines, engines, submarines– Pressure keeps them safe and working right.

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1. Wave Interference:Waves mix — they get louder (beats) or form patterns (diffraction). 2. Quantum Waves:Tiny particles act like waves. We can’t know exactly where they are. 3. Seismic Waves:Earthquake waves show Earth’s inside layers by how they travel. 4. Sound in Medicine:Ultrasound shows body parts. Some sounds heat or test tissues. 5. Gravitational Waves:Big space crashes make ripples. We "hear" them to learn about space. 6. Faster Than Sound/Light:Faster than sound = boom!Faster than light in water = glowing blue flash.

1. Sound in Warm vs Cold Air:Warm air = faster particles → sound travels faster.Cold air = slower particles → sound is slower. 2. How We Hear Direction and Distance:Your brain compares sound in both ears to tell where and how far it is. 3. Echoes and Acoustics:Echo = sound bouncing back.Good acoustics = sound reflects just right so it’s clear. 4. Ultrasound in Medicine:High sound waves go into the body and bounce back to make pictures. 5. Sound as Energy:Yes, but sound is weak, so it’s hard to get useful energy from it.

1. Why use optical fiber instead of copper?* Faster * Carries more data * Goes longer distances * No signal interference * Lighter and thinner 2. Where is it used?* Internet and phones * TV * Medical tools * Military * Sensors 3. How does it send data?Light carries data and bounces inside the cable using reflection. Repeaters boost the signal. 4. Single-mode vs Multi-mode:* Single-mode: For long distances, one light path * Multi-mode: For short distances, many light paths 5. How does light stay inside?The light bounces inside the core and cladding. It doesn’t escape because of total internal reflection.

1. Space Mirror:Yes, it can reflect sunlight to Earth, but it's hard to control and could affect nature. 2. Mirages:Hot air bends light, so it looks like water, but it's just light from the sky. 3. Invisibility:Special materials can bend light around objects, making them hard to see. 4. Spoon Trick:Back shows a tiny upright image. Front flips your face if you're close. 5. Laser Bounces:A laser loses some power with each bounce. It gets weaker over time. 6. Camouflage:Reflective or screen-based materials can copy the background, helping you blend in.

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✅ Mass = How much stuff is in an object (kg). ⚖️✅ Velocity = Speed + Direction (e.g., 50 km/h east). 🚗✅ GPE vs. KE 🎢 * GPE = Stored energy (height). 🏔️ * KE = Moving energy. ⬇️ 💡 GPE turns into KE when falling! * ✅ GPE = Stored energy (height) 🏔️ ✅ KE = Moving energy ⬇️ 💡 GPE → KE when falling! 🎢

 1️⃣ Types & Changes * Motion → Electricity (wind turbine). * Food → Heat (digestion). * Sun → Plants (photosynthesis). 2️⃣ Energy Rule⚖️ Energy is never lost, just changes form! (Pendulum swings 🎯). 3️⃣ Efficiency * More efficiency = Less waste. * LED bulbs save energy! 💡 4️⃣ Kinetic Energy (KE) KE=1/2mv2 Depends on mass & speed. 5️⃣ Speed & KE🚗 Double speed = KE x4! 6️⃣ KE Changes Form * Brakes → Heat * Ball bounces → KE ↔ GPE * Motors → Electricity → Motion

1.Butterflies don’t have mouths! They use a long straw-like tube called a proboscis to drink nectar, fruit juice, and water. 1. How Long Do They Live? ⏳ 2. Small butterflies – 1-2 weeks 3. Big butterflies – 2-6 weeks 4. Some special ones – Up to 9 months Butterflies have short lives but make the most of it! 🌸✨ 1. No, butterflies have different ways to stay safe! 🦋🚫 1️⃣ Hiding – Blends in with leaves 🍂2️⃣ Bright Colors – Warns predators 🧡⚠️3️⃣ Mimicry – Copies poisonous butterflies 🦋4️⃣ Fast Flying – Escapes quickly 💨5️⃣ Fake Eyes – Scares predators 👀 Each butterfly has its own special defense! 🌿✨

1️⃣ Friction & Mechanical Energy * Friction reduces mechanical energy by turning it into heat & sound. 2️⃣ Energy Equation ME=PE+KEME = PE + KEME=PE+KE * Potential Energy (PE) = mgh (stored energy). Kinetic Energy (KE) = ½ mv² (motion energy). 3️⃣ Mechanical Energy in Renewables * Wind → Spins turbines → Electricity ⚡. * Hydro → Falling water turns turbines → Electricity ⚡. 4️⃣ Mechanical vs. Other Energy * Mechanical = Motion & position. * Thermal = Heat. * Electrical = Moving electrons. 5️⃣ Mechanical Energy in Sports * Kicking a ball: PE → KE → PE. * Swinging a bat: KE transfers to the ball, making it fly.

1️⃣ How Melanism Helps 🐆* Camouflage (better hiding). * Absorbs heat (warmer in cold places). * Stronger immunity (possible disease resistance). 2️⃣ Industrial Melanism 🏭* Pollution made dark moths survive (better camouflage on soot-covered trees). * Example of natural selection! 3️⃣ Melanistic Animals 🖤* Black panthers (leopards/jaguars). * Melanistic wolves, foxes, squirrels, snakes, birds. 4️⃣ How It Affects Survival* Better for night hunting. * Prey blends into dark forests. * Some animals avoid them (seen as rare/dangerous). 5️⃣ What Causes It? 🧬* Genetic mutation → More melanin. * Can be dominant or recessive. 6️⃣ Melanism in Humans? 👤* Yes! More melanin = darker skin, hair, eyes. * Helps protect from the sun.

1️⃣ Earth Without Atmosphere 🌍🚀* Sun’s energy still reaches Earth (radiation). * Day = 🔥 Super hot (~250°F) * Night = ❄️ Freezing cold (~-250°F) * No weather, no clouds, just extremes! 2️⃣ Heated Object in a Vacuum 🏺🔥* No air → No conduction or convection. * Only cools by radiation (slowly emits heat). * Like satellites in space! 🚀

1️⃣ Mechanical vs. Electrical Energy Transfer * Mechanical: Moves objects (gears, turbines). * Electrical: Moves electrons (wires, circuits). 2️⃣ Energy in Renewables * Solar: Light → Electricity. * Wind: Wind → Turbine → Electricity. * Hydro: Water → Turbine → Electricity. 3️⃣ Energy Loss & Reduction * Loss: Heat, sound, friction. * Fix: Lubrication, better materials, insulation. 4️⃣ Convection in Fluids * Hot rises, cold sinks → creates a cycle. * Examples: Boiling water, sea breeze. 5️⃣ Radiation (No Medium Needed!) * Energy moves in waves (like sunlight to Earth). 6️⃣ Thermal Conductivity & Insulation * Conductors: Metal (transfers heat fast). * Insulators: Wood, plastic (slows heat transfer).

1️⃣ Mechanical vs. Electrical Energy Transfer * Mechanical: Moves objects (gears, turbines). * Electrical: Moves electrons (wires, circuits). 2️⃣ Energy in Renewables * Solar: Light → Electricity. * Wind: Wind → Turbine → Electricity. * Hydro: Water → Turbine → Electricity. 3️⃣ Energy Loss & Reduction * Loss: Heat, sound, friction. * Fix: Lubrication, better materials, insulation. 4️⃣ Convection in Fluids * Hot rises, cold sinks → creates a cycle. * Examples: Boiling water, sea breeze. 5️⃣ Radiation (No Medium Needed!) * Energy moves in waves (like sunlight to Earth). 6️⃣ Thermal Conductivity & Insulation * Conductors: Metal (transfers heat fast). * Insulators: Wood, plastic (slows heat transfer).

 Friction & Mechanical Energy * Friction reduces mechanical energy by turning kinetic energy into heat. 2️⃣ Energy Equation ME=PE+KEME = PE + KEME=PE+KE * Potential Energy (PE): PE=mghPE = mghPE=mgh * Kinetic Energy (KE): KE=12mv2KE = \frac{1}{2} mv^2KE=21​mv2 3️⃣ Mechanical Energy in Renewable Power * Wind: Wind turns turbines → mechanical → electrical energy. * Hydro: Water falls → kinetic spins turbines → electrical energy. 4️⃣ Mechanical vs. Other Energy * Mechanical = Motion & position. * Thermal = Heat. * Electrical = Moving electrons. 5️⃣ Sports & Mechanical Energy * Kicking a ball: PE → KE → PE as it moves. * Swinging a bat: KE transfers to the ball for motion.

1. What is Melanism?Melanism is when an animal has extra black color in its fur, skin, or scales. 2. How Does Melanism Help Animals?* Hiding (Camouflage) – Dark animals blend into the night or shadows. * Staying Warm – Black fur absorbs heat, helping in cold places. * Protection from the Sun – Extra melanin blocks harmful sunlight. 3. What is Industrial Melanism?Pollution made trees darker, so black moths survived better than white ones. This is natural selection – the strongest survive and pass on their traits. 4. Animals with Melanism🐆 Black Panthers (Jaguars & Leopards) – Still have hidden spots.🐺 Black Wolves – Found in North America.🐍 Black Snakes – Like some rattlesnakes & cobras.🐿 Black Squirrels – Common in some forests.🦅 Black Birds – Like some hawks and owls. 5. Is Melanism Good or Bad?✅ Helps with hunting & hiding.❌ Can cause overheating in hot areas. 6. What Causes Melanism?A genetic mutation makes the body produce more melanin (black pigment). 7. Does Melanism Happen in Humans?Very rare! Some people have darker skin naturally, but true melanism is extremely uncommon. Melanism is nature’s way of helping animals survive! 🌿🐾