• # question_answer A person brings a mass of 1 kg from infinity to a point 'A'. Initially the mass was at rest but it moves at a speed of 2m/s as it reached A. The work done by the person on the mass is -3J. The potential at 'A' is:                A) $-3J/kg$ B) $-2J/kg$ C) $-5J/kg$ D) none of these

 [c]$W=({{U}_{f}}-{{U}_{i}})+({{K}_{f}}-{{K}_{i}})=m({{V}_{f}}-{{V}_{i}})+({{K}_{f}}-{{K}_{i}})$ $-3=1({{V}_{A}}-0)+\frac{1}{2}\times 1\times {{(2)}^{2}}-0$ $\therefore$${{V}_{A}}=-5J/kg$