JEE Main & Advanced
Physics
NLM, Friction, Circular Motion
Question Bank
Second Law of Motion
question_answer
A body of mass 2 kg is hung on a spring balance mounted vertically in a lift. If the lift descends with an acceleration equal to the acceleration due to gravity ?g?, the reading on the spring balance will be [NCERT 1977]
A) 2 kg
B) \[(4\times g)\,kg\]
C) \[(2\times g)\,kg\]
D) Zero
Correct Answer:
D
Solution :
Reading on the spring balance = m (g ? a) and since a = g \ Force = 0