First lets calculate the volume of the silver cube

The length of a side = 0.62 m

Volume of the cube  = (0.62 m)^3

                             = 0.238328 m^3

The density of silver is given as, 10.5g/cm^3

lets convert that into kg/m^3

density of silver = (10.5 g/cm^3)x(10^6 cm^3/m^3) x (0.001 kg/g)

                       = 10500 kg/ m^3

Hence the weight of the silver cube ,

=> 0.238328 m^3 x 10500 kg/ m^3

=> 2502.444 kg