7salt water containing 1.92 lb/gal of salt flows at a fixed rate of 2 gal/min into a 100 gal tank, initially filled with fresh water. the density of the incoming solution is 71.8 lb/ft3. the solution, kept uniform by stirring, flows out at a fixed rate of 19.2 lb/min. how many pounds of salt will there be in the tank at the end of 1 h and 40 min? what is the upper limit for the number of pounds of salt in the tank if the process continues indefinitely? how much time will elapse while the quantity of salt in the tank changes from 100 to 150 lb?

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.

the answer is a for sure mark brainliest i had got this right on usatestprep