Q.2 Angular Momentum The most repeated concept in NEET Shrinking Earth Problem 2026 скачать в хорошем качестве

Q.2 Angular Momentum The most repeated concept in NEET Shrinking Earth Problem 2026

IThe core principle here is the Law of Conservation of Angular Momentum. If no external torque acts on a system (like the Earth suddenly shrinking due to internal gravity), its total angular momentum remains constant.The Physics BreakdownWhen the Earth shrinks, its mass ($M$) stays the same, but its radius ($R$) decreases. Since the Earth is modeled as a solid sphere, we use the following relationships:Moment of Inertia ($I$): For a solid sphere, $I = \frac{2}{5}MR^2$.Angular Momentum ($L$): $L = I\omega$, where $\omega$ is the angular velocity.Conservation Law: Since there is no external torque, $L_{initial} = L_{final}$.The Step-by-Step LogicIf the Earth’s radius shrinks from $R_1$ to $R_2$:Inertia Drops: Because $I \propto R^2$, a smaller radius means a much smaller moment of inertia.Speed Increases: To keep $L$ constant, the angular velocity $\omega$ must increase.Time Period ($T$): Since $\omega = \frac{2\pi}{T}$, if $\omega$ goes up, the time period $T$ (the length of a day) must go down. The Earth spins faster, and the day gets shorter.The Numerical FormulaTo solve NEET-style problems, use this ratio derived from $I_1\omega_1 = I_2\omega_2$:$$\frac{2}{5}MR_1^2 \left(\frac{2\pi}{T_1}\right) = \frac{2}{5}MR_2^2 \left(\frac{2\pi}{T_2}\right)$$This simplifies beautifully to:$$R_1^2 / T_1 = R_2^2 / T_2$$OR$$T_2 = T_1 \left( \frac{R_2}{R_1} \right)^2$$ #NEETPhysics #RotationalMotion #PhysicsTricks #NEET2026 #PhysicsConcepts #AngularMomentum #MedicalEntrance #JEE #jeeaprilattempt #jeejanuaryattempt #jeeadvanced #mhtcetlatestupdates #kcet #rotationalmotion #education #physicstricks #SHORTCUTSINPHYSICS #physics #ncertsolutions #ncertphysics #neetncert#2025 Rank Saver #📉: Don't let tough Physics kill your rank again. •#2. @600# Elite Questions 🎯: Master 600 models; cover 100% concepts. •3. @#Target 150+ Marks 🏆: Lock in your score with surgical precision. •4. @#2-Hour Daily Limit ⏳: Max results in minimum time—save energy for Bio. •5. @#40-Day Masterplan 🗓️: 15 numericals a day to finish the entire syllabus. •6. @#Concept Clarity 💡: We teach the "Why," not just the solution. •7. @#Live Doubt Marathons 🏃‍♂️: Weekly live sessions to clear every hurdle. •8. @#5 Full PCB Mock Tests 📝: Realistic 720-mark practice for exam grit. •9. @#Darna Mana Hai 🛡️: Zero stress. One platform. Total confidence. 10. @#Just ₹2500 💎: Premium coaching at the best price. Watch demos now!