A bird is sitting a wire cage hanging from the spring balance. Let the reading of the spring balance be W1 . If the bird flies about inside the cage, the reading of the spring balance becomes W2 . Which of the following is true?

Correct answer: W₁ > W₂

Explanation: When a bird flies inside a cage, the weight reading decreases (W₁ > W₂) as air currents reduce direct pressure on the cage base. 📚 Other Information: ▪️ When bird sits, full weight is transferred to cage (W₁). ▪️ When flying, bird pushes air downwards → some force is carried by moving air, reducing cage pressure. ▪️ Spring balance measures vertical force transmitted. ▪️ Demonstrates Newton’s 3rd law of motion. ▪️ Similar concept applies to helicopters in hovering. ▪️ In physics, this is studied under mechanics and forces. ▪️ If cage is airtight, effect reduces as air recirculates. ▪️ Shows relation between weight, lift, and buoyant force.