00:01
Hello students, in this question given as the volume value is 0 .5 meter cube of the refrigerant and their mass is 10 kilogram and at temperature t is equals to minus 20 degree celsius.
00:17
In the first part of the question we have to find the pressure.
00:22
Now from the refrigeration table of r134a at temperature minus 20 degree celsius, pressure saturated pressure is equals to 132 .82 kilo pascal.
00:49
In the next part of the question we have to find the total internal energy.
00:56
So for this from that table at the temperature minus 10 degree celsius, specific volume of the fluid is equals to from that table 0 .0007362 meter cube per kilogram and the specific volume of the gas is equals to 0 .14729 meter cube per kilogram.
01:25
Now we will write the specific volume of the refrigerant.
01:30
So specific volume is volume by mass.
01:35
So volume is given in this question is 0 .5 and mass is 10.
01:38
So this is equals to 0 .05 meter cube per kilogram.
01:44
Now we will substitute their values in the equation v is equals to vf plus x vfg phase.
01:55
Now we will substitute their values v is 0 .05 vf is 0 .0007362 plus x in bracket vfg means vf minus vg minus vf.
02:10
So vg is equals to 0 .14729 minus 0 .0007362.
02:18
So after calculation we will get this x is equals to 0 .3363.
02:28
Now we will use this value further.
02:31
Now first we will calculate the specific internal energy...