JEE Main Physics question
A spring balance is attached to the ceiling of a lift. A man hangs his bag on the spring, and the spring reads 49 N when the lift is stationary. If the lift moves downward with an acceleration of 5 m/s², the reading of the spring balance will be
Answer: (B)
Solution
At rest, mg = 49 N ⟹ m = 4.9 kg. Moving down with a = 5 m/s², reading = m(g − a) = 4.9 × (10 − 5) = 24.5 N ≈ 24 N.