Verified Solution • 2025–26 Session moderate

QJEEM_2025_4: JEE Main 2025 Physics - Class 11 JEEM_2025_4 Solution: A balloon and its content having mass M is moving up with an…

A balloon and its content having mass M is moving up with an acceleration ‘a’. The mass that must be released from the content so that the balloon starts moving up with an acceleration ‘3a’ will be (Take ‘g’ as acceleration due to gravity)

Multiple Choice Options

  • A
    3Ma2a+g\frac{3Ma}{2a + g}
  • B
    2Ma3a+g\frac{2Ma}{3a + g}
  • C
    3Ma2a−g\frac{3Ma}{2a - g}
  • D
    2Ma3a−g\frac{2Ma}{3a - g}

Step-by-Step Verified Solution

Your derivation is perfectly structured and mathematically sound. Here is the final solution formatted for maximum clarity, incorporating free-body diagram references to visualize the forces. --- ## **Solution: Mass to be Released from an Accelerating Balloon** To solve this, we analyze the forces acting on the balloon using Newton's Second Law (). We assume the **Upthrust** (buoyant force) remains constant in both scenarios. ### **1. Initial State** The balloon has total mass and is accelerating upward at . * **Upward Force:** Buoyant force * **Downward Force:** Weight Applying the equation of motion: --- ### **2. Final State** A mass is released, so the new mass is . The new upward acceleration is . * **Upward Force:** Buoyant force * **Downward Force:** New weight Applying the equation of motion for the new mass: --- ### **3. Algebraic Substitution** Substitute the value of from **Eq. 1** into **Eq. 2**: **Expand both sides:** **Cancel and simplify:** **Rearrange to group terms with :** --- ### **4. Final Result** Solving for : **Conclusion:** The mass that must be released is given by **Option (B)**.

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