Doubtify – JEE Ki Taiyaari, Simple Bhasha Mein

  🎬 Restitution ka Concept – Ekdum Easy! "Jab do objects takraate hain, to unke bounce back karne ki ability ko hi bolte hain Coefficient of Restitution!" ⚡ What is Coefficient of Restitution (e)? Formula: e = (Relative speed after collision) / (Relative speed before collision) It tells us how “bouncy” a collision is. Simple! 🧠 Important Points to Remember: 0 < e < 1 → Partially Elastic Collision (thoda bounce, thoda energy loss) e = 1 → Perfectly Elastic Collision (poora bounce, no energy loss) e = 0 → Perfectly Inelastic Collision (no bounce, objects stick together) 🧪 Real-Life Example: Let’s say a ball hits the ground : If e = 0.8 → Ball bounce karegi, par speed thodi kam hogi If e = 0 → Ball bilkul waapas nahi aayegi (stick to ground) ❗ Memory Trick (Easy Yaad Karne Ke Liye): e = After / Before Numerator = After collision Denominator = Before collision Bas itna yaad rakho! 📢 Conclusion: "Bounce kitna hoga?...

  🔬 Bulk Modulus Concept – Find Initial Volume | Doubtify JEE 📌 Question: A sample of a liquid is kept at 1 atm . It is compressed to 5 atm , which leads to a change of volume of 0.8 cm³ . If the bulk modulus of the liquid is 2 GPa , the initial volume of the liquid was ______ litre . (Take 1 atm = 10⁵ Pa) 🖼️ Question Image:

🚆 Train Crossing Concept in 59 Seconds | Doubtify JEE Shorts 📌 Question: Ever wondered how long one train takes to pass another or a platform? The Train Crossing Concept helps solve such questions in seconds using speed-distance fundamentals.

  📌 Newton’s Law of Cooling – Explained for JEE | Formula + Graph + Example 🖼️ Image:

  🧪 Young’s Modulus from Wire Extension | JEE Physics | Doubtify 📌 Question: A 3 m long wire of radius 3 mm shows an extension of 0.1 mm when loaded vertically by a mass of 50 kg in an experiment to determine Young's modulus. The value of Young’s modulus of the wire as per this experiment is P × 10¹¹ N/m² , where the value of P is: (Take g = 3π m/s²) 🖼️ Question Image:

  🏐 Momentum vs Height Graph – Vertical Motion | JEE Physics | Doubtify JEE 📌 Question: A ball is thrown vertically upwards (take +z-axis as upwards) from the ground. 👉 Which of the following momentum-height (p–h) graphs correctly represents the motion? This is a concept-based question that checks your understanding of vector momentum and energy conservation . 🖼️ Question Image:

  ⚖️ Tension in Strings in Orbiting Satellite – Electrostatics in Space | JEE Physics | Doubtify JEE 💡 Question: Two identical small bodies each of mass = m and charge = q are suspended from two strings of length = l from a fixed point. The system is taken inside an orbiting artificial satellite . 👉 Question: What is the tension in the strings inside the satellite? 🖼️ Question Image:

  🚢 Minimum Distance Between Two Moving Ships – Relative Motion | JEE Physics | Doubtify JEE 💡 Question: Ship A is sailing towards the north-east with velocity v = 30 î + 50 ĵ km/h , where î points east and ĵ points north . Ship B is located at a distance of 80 km east and 150 km north of ship A and is sailing towards the west at 10 km/h . Question: After how much time will Ship A be at a minimum distance from Ship B ? 🖼️ Question Image:

  📈 Acceleration as a Function of Distance – Motion in One Dimension | JEE Physics | Doubtify JEE 🧮 Question: The distance x covered by a particle in one-dimensional motion varies with time t as: x² = at² + 2bt + c . If the acceleration of the particle depends on x as x⁻ⁿ , where n is an integer, what is the value of n ? 🖼️ Question Image: ✅ Detailed Concept & Solution: This is a JEE-level conceptual problem involving the relation between distance, velocity, and acceleration — with a twist of functional dependence. We are given: x² = at² + 2bt + c — (1) To find acceleration and its dependency on x , let’s differentiate both sides of equation (1): Differentiate w.r.t. time t : 2x(dx/dt) = 2at + 2b ⇒ v = dx/dt = (at + b)/x — (2) Now differentiate velocity v w.r.t time to find acceleration: a = dv/dt = d/dt[(at + b)/x] Use quotient rule: a = [a·x - (at + b)(dx/dt)] / x² Plug dx/dt = (at + b)/x from (2): a = [a·x - (at + b)·((at + b)/x)] / x² ⇒ ...

  ⏱️ Acceleration-Time Graph – Find Time When Initial Velocity is Regained | JEE Physics | Doubtify JEE ❓ Question: The acceleration-time graph of a particle is as shown. At what time does the particle acquire its initial velocity again?

🔄 Circular Motion | Physics | Doubtify JEE

🎯 Question: A balloon was moving upwards with a uniform velocity of 10 m/s. An object of finite mass is dropped from the balloon when it was at a height of 75 m from the ground level. The height of the balloon from the ground, when the object strikes the ground, was around: (Take g = 10 m/s²)

     📌 Question: Water droplets are coming from an open tap at a particular rate. The spacing between a droplet observed at the 4th second after its fall to the next droplet is 34.3 m . At what rate are the droplets coming from the tap? (Take g = 9.8 m/s²) 🖼️ Question Image:

    🧲 Motion in a Plane  |  Physics |  Doubtify JEE 💡 Question: A mosquito is moving with a velocity  v = 0.5 t² î + 3t ĵ + 9 k̂ m/s and accelerating in uniform conditions. What will be the direction of motion of the mosquito after 2 seconds? 🖼️ Question Image: 🔬 Concept Overview: This is a vector motion problem where you're given a time-dependent velocity vector in three dimensions. To find the direction of motion , we must compute the velocity vector at  t = 2 t  =  2 seconds and then determine its direction using unit vector analysis or angle calculation with respect to axes. This is a key concept from the chapter "Motion in a Plane" , often asked in JEE Mains or Advanced. 🧠 Step-by-Step Explanation: Given: v ⃗ ( t ) = 0.5 t 2 i ^ + 3 t j ^ + 9 k ^ \vec{v}(t) = 0.5t^2 \hat{i} + 3t \hat{j} + 9 \hat{k} At t = 2 t = 2  seconds: i-component: 0.5 × 2 2 = 2   m/s j-component: 3 × 2 = 6   m/s 3 \times 2 = 6 \, \text{m/s} ...

  🧲 Motion in a Straight Line  |  Physics |  Doubtify JEE 💡 Question: A car accelerates from rest at a constant rate α for some time, after which it decelerates at a constant rate β to come to rest. If the total time elapsed is t seconds, the total distance traveled is: 🖼️ Question Image: 🧠 Solution (Image): 🎥 Video Solution: 🔍 Why this Question is Important: This is a classic and conceptual question from Kinematics , frequently appearing in JEE Main exams. It tests your understanding of uniformly accelerated and retarded motion, and time-division-based distance calculation – a vital part of motion in a straight line. 📩 Have a Doubt? Drop us a mail at  doubtifyqueries@gmail.com  or DM us on  Instagram . Stay consistent. Watch – Pause – Solve – Repeat. Team Doubtify is with you till the finish line! 💪

  🧪Motion in a Straight Line  | Physics |  JEE Mains ❓ Question: A person goes to his office from his home daily at a fixed speed. But today he decided to reduce his speed by 20%, and as a result, he reaches his office 16 minutes late. What's the actual/original time he takes to reach his office daily? 🖼️ Question Image: 🧠 Solution (Image): 🎥 Video Solution: 🔍 Why this Question is Important: This is a frequently asked conceptual problem in  Kinematics  that tests your understanding of the relationship between speed, time, and distance. It’s a perfect example of how real-life reasoning can be applied to JEE Physics problems — and a favorite in  JEE Mains  question banks. 📩 Have a Doubt? Drop us a mail at  doubtifyqueries@gmail.com  or DM us on  Instagram . Stay consistent. Watch – Pause – Solve – Repeat. Team Doubtify is with you till the finish line! 💪

🧪 Kinematics – Motion in a Straight Line | Physics | JEE Mains 📌 Question: A stone is dropped from the top of a building.  When it crosses a point 5 m below the top , another stone starts to fall from a point 25 m below the top , and both stones reach the bottom of the building simultaneously . Find the height of the building . (Take g = 10 m/s²) 🖼️ Question Image: 🧠 Solution (Image): 🎥 Video Solution: 🔍 Why this Question is Important: This is a  classic conceptual question from Kinematics , commonly asked in  JEE Mains  and other engineering entrance exams. It checks your understanding of  relative motion ,  free fall , and  time equations of motion  – topics that are often mixed to form trick questions. 📩 Have a Doubt? Drop us a mail at  doubtifyqueries@gmail.com  or DM us on  Instagram . Stay consistent. Watch – Pause – Solve – Repeat. Team Doubtify is with you till the finish line! 💪