Question

131 is contained in a piston cylinden ayso with a cvoRtsetin aeamand initial volume ?Cm,3 the cun eJlnitially at- loo kPa and 20? Connected to the piston (usefigut less) is apvin a constaudt of loG c ndping initially ondeooimed Hou mudh heat mut be odded to ab to inereaye the pnes sude to 3ookpa kloo N/emand Spoing Cm) VI = 20 CM3-20x10-6 m3 PI VI P2 30okPa

Answer 1

Given v_1 = 20 cm^3 P_1 = 100 Kpa T_1 = 20 degree C = 293 K P_2 = 300 kpa P_1v_1 = mR T_1 m = (100) (20 times 10^-6)/0.287 times 293 = 2.37 times 10^-5 kg \r\n P_2 = F/A = Kx/A 300 times 1000 = (100 N/m times 1 cm/0.01 m) x/(4 times 10^-4 m^2) x = 0.012 m Ax = v-2 - v_1 (4 times 10^-4) (0.12) = v_2 - (20 times 10^-6) v_2 = 2.48 times 10^-5 m^3 P_2 v_2 = mRT_2 T_2 = (300 Kpa) (2.48 times 10^-5)/0.287 times 2.37 times 10^-5 T_2 = 1093.8 k \r\n Heat added to air Q = mCv (T_2 - T_1) + (P_1 + P_2)/2 (v_2 - v_1) = (2.37 times 10^-5) (0.718) (1093.8 - 293) + (100 + 300)/2 (2.48 - 2) times 10^-5 Q = 0.0013 KJ Q = 13 J