Understanding Weight and Acceleration in a Bird's Flight Using Physics

[vipulgoyal]

Homework Statement

A bird is sitting in a large closed cage which is placed on a spring balance. It records a weight of
25 N. The bird (mass = 0.5 kg) flies upward in the cage with an acceleration of 2 m/s2. The spring
balance will now record a weight of -

Homework Equations

The Attempt at a Solution

i tried by calculating the mass of the spring balnce and then calculating the weight but the answer says same as earlier!1

 

[supratim1]

the weight will be same, as the cage is closed. total mass is constant. weight = mg.

 

[vipulgoyal]

the weight will be same, as the cage is closed. total mass is constant. weight = mg.

bird is not sitting now i mean its flapping its wings so that it is not in contact with the bars of the cage howz mass constant then

 

[vipulgoyal]

Does anyone know a way out of this prob??

 

[supratim1]

the weight of the bird is supported by flapping its wings, which creates air pressure on the bottom of the cage. mass is always conserved.