Question

A body of mass 4 kg weighs 4.8 kg when suspended in a moving lift. The acceleration of the lift is

• A. $9.80ms^{- 2}$ downwards
• B. 9.80$ms^{- 2}$ upwards
• C. 1.96$ms^{- 2}$ downwards
• D. 1.96$ms^{- 2}$ upwards

Answer 1

Answer: (D)

1.96$ms^{- 2}$ upwards

Answer 2

As the apparent weight increase therefore we can say that acceleration of the lift is in upward direction.

$R = m(g + a)$ ⇒$4.8\mspace{6mu} g = 4(g + a)$

⇒$a = 0.2g = 1.96\mspace{6mu} m/s^{2}$