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

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 (A) 24 N (B) 74 N (C) 15 N (D) 49 N

Tardigrade Admin · Accepted Answer

In stationary position, spring balance reading =mg=49 m=(4.9/9.8)=5 kg When lift moves downward. mg-T=ma Reading of balance T=mg-ma =5(9.8-5) =5× 4.8 =24 N

Q. 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 $5 m / s^{2},$ the reading of the spring balance will be

24 N

74 N

15 N

49 N

In stationary position, spring balance reading
$= m g = 49$ $m = \frac{4.9}{9.8} = 5 k g$ When lift moves downward. $m g - T = ma$ Reading of balance $T = m g - ma$ $= 5 (9.8 - 5)$ $= 5 \times 4.8$ $= 24 N$

Q. 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 5m/s2, the reading of the spring balance will be