An ideal monoatomic gas is confined by a spring loaded massless piston of cross-section $8\times {10}^{-3}{m}^2$ . Initially the gas is at 300 K and occupies a volume of $2.4\times {10}^{-3}{m}^3$  and the spring is in its relaxed state. The gas is heated by an electric heater until piston moves out without friction by 0.1 m. Force constant of the spring is 8000 N/m, atmospheric pressure $1\times {10}^5$  N/m, the cylinder and piston are thermally insulated, the piston and spring are massless and there is no friction between the piston and cylinder. Neglect the heat lost through the wire of the heater. The heat capacity of the heater is neglected.