Isothermal process W=nrt ln(v2/v1)
The Attempt at a Solution
I got the workdone then sub into the equation of isothermal process. i couldn't get the answer right
michealyap said:I understand the relationship of pressure p and volume V for isothermal process. P1V1 = P2V2. In the question i know V1,V2, and P1 i take as 1.039bar. Then ended up P2 is a wrong answer.
michealyap said:Mass in room + mass in tank = Pr1*Vr1 / RT + Pt1*Vt1 /RT - Initial state.
Mass in room + mass in tank = Pr2*Vr2 /RT + Pt2*Vt2 /RT - final state
michealyap said:At here we know Pr1,Vr1, Pt1, Vt1, but we don't know Pr2 and Pt2 and also Vr2 and Vt2, but we know the Vr2+Vt2 =
michealyap said:Yes, i also agree we don't know Pr2 and Pt2 which is what we want to find. we don't know pt1 as well. Even with those equations we can not find three unknow with only two equations.
michealyap said:yeah. we still unable to solve it right, we just know it is equal. the equation will become
Pr1*Vr1 + Pt1*Vt1 =Pr2*Vr2 + Pt2*Vt2 , let Pt2 = Pr2 = Peq,
Pr1*Vr1 + Pt1*Vt1 =Peq*Vr2 + Peq*Vt2 , we do not know the Pt1 and Peq.
michealyap said:a) How i do it P=FA = 900kg * 9.81/2.25 = 3924 Pa since Pr1 is 1.0 bar the and the elevator is not lifted. so the pressure necessary to elevate is 1.039 bar. which i presume is Pr1.
michealyap said:Yes.. You are right. Wao.. This is amazing.. I thought when it reached equilibrium the tank will also have the same pressure as the room..but why we can assume pt2 to be same in the room pr2.
Please take more care in writing your equations. At the very least, indicate exponents by using ^, as in v1 = .23m^3 and v2 = 1 m^3.michealyap said:v1=0.23m3
michealyap said:Based on your interpretation, I fully understand what we have been.doing..