Question Detail
Question
Find the mass of an object attached to the hook of a spiral balance which is vertically attached to the roof of a lift. The reading on the spring balance when the lift goes down with an acceleration of 0.1 m/s² is 29.7 N.
Correct Answer
Option B is the correct answer.
Detailed Explanation
When the lift accelerates downward, the apparent weight is m(g - a). Given reading = 29.7 N, a = 0.1 m/s², g = 9.8 m/s². So m(g - a) = 29.7 => m(9.8 - 0.1) = 29.7 => m(9.7) = 29.7 => m = 29.7/9.7 = 3.06 kg ≈ 3.00 kg.
Hint
Apparent weight in a downward accelerating lift is m(g - a).