In a previous section we looked at mixing problems in which the volume of fluid remained constant and saw that such problems give rise to separable equations. (see example.) if the rates of flow into and out of the system are different, then the volume is not constant and the resulting differential equation is linear but not separable. a tank contains 400 l of water. a solution with a salt concentration of 0.4 kg/l is added at a rate of 5 l/min. the solution is kept mixed and is drained from the tank at a rate of 3 l/min. if y(t) is the amount of salt (in kilograms) after t minutes, show that y satisfies the differential equation dy dt = 2 − 3y 400 + 2t . solve this equation and find the concentration after 20 minutes. (round your answer to four

In a laboratory experiment, a fermenting aqueous solution of glucose and yeast produces carbon dioxide gas and ethanol. the solution was heated by burning natural gas in a bunsen burner to distill the ethanol that formed in the flask. during the distillation, the ethanol evaporated and then condensed in the receiving flask. the flame of the burner was kept too close to the bottom of the flask and some of the glucose decomposed into a black carbon deposit on the inside of the flask. during this experiment the following changes occurred. which of these changes involved a physical change and not a chemical change? check all that apply. 1-condensation of ethanol 2-evaporation of ethanol 3- formation of carbon dioxide gas from glucose burning of natural gas 4-formation of ethanol from glucose by yeast 5-formation of a carbon deposit inside the flask

Compare and contrast refraction of light and sound will give brainliest

Select the correct value for the indicated bond angle in each of the compounds. o−o−oo−o−o angle of o3 90° 109.5° < 109.5° 120° < 120° 180° f−b−ff−b−f angle of bf3 180° < 109.5° < 120° 120° 109.5° 90° f−o−ff−o−f angle of of2 < 120° 120° 90° 109.5° 180° < 109.5° cl−be−clcl−be−cl angle of becl2 90° 109.5° 180° 120° < 109.5° < 120° f−p−ff−p−f angle of pf3 90° 109.5° < 109.5° 180° 120° < 120° h−c−hh−c−h angle of ch4 90° < 109.5° 180° 120° < 120° 109.5°