Laws Of Motion Question 376
Question: 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 m = 0.5 kg) flies upward in the cage with an acceleration of $ 2m/s^{2} $ . The spring balance will now record a weight of [MP PMT 1999]
Options:
A) 24 N
B) 25 N
C) 26 N
D) 27 N
Show Answer
Answer:
Correct Answer: B
Solution:
Since the cage is closed and we can treat bird, cage and the air as a closed (isolated) system. In this condition the force applied by the bird on cage is an internal force, due to this the reading of spring balance will not change.