According to the scientific observation that energy is conserved in a "closed system,” no machine can do work on its surrounding environment forever. this observation has been made over and over again in all sciences, and no example has been found that disproves the fact of conservation of energy. the fact that energy is always conserved in a closed system is what type of scientific statement? a law a theory an inquiry a hypothesis

Onsider a u-tube whose arms are open to the atmosphere. now, equal volumes of water (ρ = 62.4 lbm/ft3) and light oil (ρ = 49.3 lbm/ft3) are poured from different arms. a person blows from the oil side of the u-tube until the contact surface of the two fluids moves to the bottom of the u-tube, and thus the liquid levels in the two arms are the same. if the fluid height in each arm is 31 in, determine the gage pressure the person exerts on the oil by blowing. (round the final answer to three decimal places.)