In the fig. given below masses \( \mathrm{m} \) and \( \mathrm{m} \...

In the fig. given below masses \( \mathrm{m} \) and \( \mathrm{m} \) ' are tied with a thread passing over a pulley, \( \mathrm{m} \) is on a frictionless horizontal surface. If acceleration due to gravity is \( g \), the acceleration of \( m^{\prime} \) in this arrangement will be :-
(1) 9
(2) \( \mathrm{m}^{\prime} \mathrm{g} /\left(\mathrm{m}+\mathrm{m}^{\prime}\right) \)
(3) \( \mathrm{mg} / \mathrm{m}^{\prime} \)
(4) \( \mathrm{mg} /\left(\mathrm{m}-\mathrm{m}^{\prime}\right) \)