\( = \,\,{W_0}\, + \,\frac{1}{2}\,m{v^2}\,........\,\,(i)\)

અને \(\frac{{hc}}{{250\,\, \times \,\,{{10}^{ - 9}}}}\,\, = \,\,{W_0}\, + \,\frac{1}{2}m{(2v)^2}\,.......\,\,(ii)\)

સમીકરમ \((i)\) ને \((ii)\) વાડેભંગતા \({\text{ }}\frac{{\text{1}}}{{\text{2}}}m{v^2}\, = \,\,\frac{{hc}}{3}\,\left[ {\frac{1}{{250\,\, \times \,\,{{10}^{ - 9}}}}\, - \,\,\frac{1}{{400\,\, \times \,\,{{10}^{ - 9}}}}} \right]\,\,\,.\)

સમીકરમ \((i)\) અને  \((ii)\) પરથી \({{\text{W}}_{\text{0}}}\, = \,\,2hc\,\, \times \,\,{10^6}\,J\,.\)