Doubtify – JEE Ki Taiyaari, Simple Bhasha Mein

  ❓ Question Why does a person feel heavier when a lift accelerates upward? 🖼️ Concept Image ✍️ Short Solution This is a pure Newton’s Second Law + apparent weight concept. No calculation needed — just force direction clarity + equation setup 🔥 🔹 Step 1 — Actual vs Apparent Weight (MOST IMPORTANT 💯) Actual weight: Actual Weight = m g \text{Actual Weight} = mg 👉 Yeh constant hota hai (Earth ki gravity par depend karta hai) Apparent weight: Apparent Weight = N \text{Apparent Weight} = N 👉 Jo tum feel karte ho = Normal Reaction 🔹 Step 2 — Normal Reaction = What You Feel 👉 Lift ke floor ka jo force tum par lagta hai, wahi: N = Apparent Weight N = \text{Apparent Weight} 📌 Weighing machine bhi N measure karti hai, mg nahi 🔹 Step 3 — Lift Moving Upward 👉 Jab lift upar accelerate karti hai , system ko upward accelerate karne ke liye extra force chahiye hota hai. 👉 Isliye floor tumhe extra push deta hai. 🔹 Step 4 — Apply Newton’s Seco...

  ❓ Question A man of mass 75 kg stands in a lift. The lift starts moving upward with an acceleration of 2 m/s² . Find the force exerted on him by the floor . 🖼️ Question Image ✍️ Short Solution This is a Newton’s Laws + apparent weight question. When lift accelerates upward → normal force increases 💯 🔹 Step 1 — Understand Forces on the Man (MOST IMPORTANT 💯) Two forces act: Upward → Normal Reaction (N) Downward → Weight (mg) Since lift is accelerating upward , net force is upward. 🔹 Step 2 — Apply Newton’s Second Law N − m g = m a N - mg = ma N − m g = ma 👉 यही सबसे important equation है 🔹 Step 3 — Substitute Values Mass: m = 75  kg m = 75 \text{ kg} Acceleration: a = 2  m/s 2 a = 2 \text{ m/s}^2 Take: g = 10  m/s 2 g = 10 \text{ m/s}^2 N − ( 75 × 10 ) = 75 × 2 N - (75 \times 10) = 75 \times 2 N − 750 = 150 N - 750 = 150 N = 900  N N = 900 \text{ N} 🔹 Step 4 — Interpret the Result 👉 Normal force = apparent weight ...