It hasn't been proven! Once you exhale, the THC would be in the user. There is such thing as feeling the effects of a contact high for some sensitive types.
No. THC is stored in fat cells. Throwing up would only cause you to throw up stomach fluids.
No.
Thc can be detected in the saliva for 5 to 10 days depending if you are a heavy user.
THC will remain in the body for 30 days for the average person. There is no trick to quicken or slower this process.
THC
No. Percocet will cause you to fail a drug test for Opium (Heroin). if you smoked marijuana recently you will also fail for THC metabolites.
No
yes sort of for THC if your a daily user it will . all other drugs are gone in 5 days only THC is stored in body fat
THC synergists could be substances, which act together with THC. They can change the activity of THC or they can create new e.g. bad effects, together with THC. THC synergists can theoretically be used to fight against Cannabis abuse. Theoretically can synergists used, which change the cannabis effect from good to very bad. But this is only an idea from me. If a THC synergists has together with THC a very heavy side effect, e.g. leads to psychosis, then the cannabis user thinks this comes from the THC and he stops the consum, if he not knows from the use of THC synergists. In case of a cannabis epidemie such synergists can be sprayed over the whole country to help the cannabis user to stop the consum. But i don't know wheather such synergists exists. Such a theoretically use also must be strong controlled by lawers and also must be top secret.
I'm assuming you mean "will THC show up on a urine test from a contact high?" (meaning you didn't actually smoke, you were buzzed by "second-smoke") to which the answer is NO. A contact high means you have less than 5% of the THC from the entire sesh in your system.
If you are an illegal drug user or indeed receiving prescribed medicines, you should NOT donate blood.