Water at 50 c is flowing in a covered irrigation ditch below ground. every 1000 ft there is a vent line each size 22.36 mm inside diameter and 30.28 cm long to the outside atmosphere at 50 c . there are 40 vents in the 1-ft ditch. the outside air can be assumed to contain 9.05% mole of water vapor . calculate the total evaporation loss of water in lbm/day and kgmol/day. assume that the partial pressure of water vapor at the surface of the water is the vapor pressure .

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.

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.