Doubtify – JEE Ki Taiyaari, Simple Bhasha Mein

  ❓ Question On an inclined plane of angle θ \theta , a block slides down with given acceleration. How do we find the coefficient of kinetic friction μ k \mu_k ​ ? 🖼 Concept Image ✍️ Short Solution This is a force resolution + Newton’s 2nd Law question. Golden idea: 👉 Resolve gravity 👉 Apply F = m a F = ma  along the plane 👉 Extract μ k \mu_k ​ 🔷 Step 1 — Forces on an Inclined Plane 💯 Inclined angle = θ \theta Gravity splits into: Along plane → m g sin ⁡ θ mg \sin\theta Perpendicular → m g cos ⁡ θ mg \cos\theta Normal reaction: N = m g cos ⁡ θ N = mg \cos\theta 🔷 Step 2 — Direction of Kinetic Friction If block slides downwards : Friction always acts upwards (opposes motion). Friction force: f k = μ k N f_k = \mu_k N f k = μ k m g cos ⁡ θ f_k = \mu_k mg \cos\theta ⚠️ Direction mistake = direct negative marking in JEE. 🔷 Step 3 — Apply Newton’s 2nd Law Along Plane Net force along plane: m g sin ⁡ θ − μ k m g cos ⁡ θ mg \sin\theta - \mu_k mg...