# Engineering questions

kquinn909
Posers and Puzzles 07 Mar '18 20:28
1. 07 Mar '18 20:28
What is the absolute pressure in a piping system when the vacuum gage reads 20" and the barometer reads 30.71" of mercury?
2. Kewpie
since 1-Feb-07
10 Mar '18 00:01
Absolutely no idea. Seems there aren't any engineers reading this forum.
3. venda
Dave
10 Mar '18 13:081 edit
Originally posted by @kquinn909
What is the absolute pressure in a piping system when the vacuum gage reads 20" and the barometer reads 30.71" of mercury?
If an answer in the 20 questions quiz was "the absolute pressure in a piping system " what category would that come under?
Presumably abstract.
In answer to the original question, when they ask these sort of questions on university challenge the answer is usually 1, minus 1 or zero so I will say the answer is 1!
4. joe shmo
Strange Egg
10 Mar '18 20:15
Originally posted by @kquinn909
What is the absolute pressure in a piping system when the vacuum gage reads 20" and the barometer reads 30.71" of mercury?
You need to state the units of pressure on the vacuum gage. If they are "inches mercury" then say that, because it isn't clear.

if they are inches mercury then the answer is

P_abs = 30.71" Hg - 20" Hg = 10.71" Hg
5. 13 Mar '18 21:37
Originally posted by @joe-shmo
You need to state the units of pressure on the vacuum gage. If they are "inches mercury" then say that, because it isn't clear.

if they are inches mercury then the answer is

P_abs = 30.71" Hg - 20" Hg = 10.71" Hg
Turns out trick question I think. So. What is 10.71" in PSI or PSIA?
6. joe shmo
Strange Egg
14 Mar '18 01:36
Originally posted by @kquinn909
Turns out trick question I think. So. What is 10.71" in PSI or PSIA?