Final answer:
To calculate the absolute pressure in the tank, add the gauge pressure of 50 psi to the atmospheric pressure. After converting the barometric reading to psi (14.29 psi), the absolute pressure is found to be 64.29 psi.
Step-by-step explanation:
To determine the absolute pressure in the tank, you need to add the gauge pressure to the atmospheric pressure. The gauge pressure is given as 50 psi. To find the atmospheric pressure in psi, we first convert the barometric reading from inches of mercury (in Hg) to psi. Using the density of mercury (PHg) which is 848.4 lbm/ft³, we know that 1 in Hg is equivalent to 0.4912 psi (since 1 in Hg = 2.03602 psi and 1 atm = 29.92 in Hg). So, the atmospheric pressure is 29.1 in Hg multiplied by 0.4912 psi/in Hg.
To calculate the atmospheric pressure (Patm) in psi from the barometric reading (29.1 in Hg):
Patm = 29.1 in Hg * 0.4912 psi/in Hg = 14.29 psi
The absolute pressure (Pabs) is the sum of the gauge pressure and the atmospheric pressure:
Pabs = Pg + Patm
Pabs = 50 psi + 14.29 psi = 64.29 psi.
Therefore, the absolute pressure in the tank is 64.29 psi.