JEE Main Physics: Acceleration on Incline Concept 💡
❓ Question A cubic block of mass m m is sliding down an inclined plane at 60 ∘ 60^\circ with an acceleration of g / 2 g/2 . Find the coefficient of kinetic friction μ k \mu_k . 🖼️ Question Image ✍️ Short Solution This is a direct Newton’s Second Law + friction problem. No tricks. Just resolve forces properly 🔥 🔹 Step 1 — Draw Free Body Diagram (MOST IMPORTANT 💯)** For block on incline at angle 60 ∘ 60^\circ : Forces acting: Weight m g mg (vertical downward) Normal reaction N N Kinetic friction f k = μ k N f_k = \mu_k N (up the plane) 🔹 Step 2 — Resolve Weight into Components Along incline: m g sin 60 ∘ mg \sin 60^\circ Perpendicular to incline: m g cos 60 ∘ mg \cos 60^\circ So normal reaction: N = m g cos 60 ∘ N = mg \cos 60^\circ 🔹 Step 3 — Apply Newton’s Second Law (Along Incline) Net force down the plane: m g sin 60 ∘ − f k = m a mg \sin 60^\circ - f_k = ma Since: f k = μ k N = μ k m g cos 60 ∘ f_k =...