question_answer

A bird is sitting on the floor of a closed glass cage and the cage is in the hand of a girl. Will the girl experience any change in the weight of the cage when the bird (i) starts flying in the cage with a constant velocity (ii) flies upwards with acceleration (iii) flies downwards with acceleration?

Answer:

                In a closed cage, the inside air is bound with the cage. (i) As the acceleration is zero, there is no change m the weight of the cage. (ii) In this case, the reaction R is given by \[R-Mg=Ma\] or \[R=M(g+a)\] Thus the cage will appear heavier than before. (iii) In this case, the reaction R is given by \[Mg-R=Ma\] or \[R=M(g-a)\] Thus the cage will appear lighter than before.