A spring balance is attached to the ceiling of a lift. When the lift is at rest spring balance reads 49 N of a body hang on it. If the lift moves: (i) Downward (ii) upward, with an acceleration of 5 ms^(-2)(iii) with a constant velocity.What will be the reading of the balance in each case?

A spring balance is attached to the ceiling of a lift. When the lift i

1.	A spring balance is attached to the ceiling of a lift. When the lift is at rest spring balance reads 49 N of a body hang on it. If the lift moves: (i) Downward (ii) upward, with an acceleration of 5 ms^(-2)(iii) with a constant velocity.What will be the reading of the balance in each case?
Answer» Solution :(i) ` R = m (g -a)` weight = 49 N so `m = (49)/(9.8) = 5kg ` `R = 5 (9.8 - 5)` R = 24 N (II) `R = m(g + a)` R = 5(9.8 +5) R = 74 N (iii) as ` a = 0 , so R = mg = 49 N`