A bird is sitting in 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 is W2. Which of the following is true ?
W1 = W2
W1 > W2
W1 < W2
nothing definite can be predicted.
when the bird will fly ,leaving the base of the cage , it would exert a force . therefore the weight must increase . please clear my doubt ?