A tank contains 400 gal of brine in which 100 lb. of salt are dissolved. Fresh water runs into the tank at a rate of 2 gal/min. The mixture, kept practically uniform by stirring, runs out at the same rate.
How much salt will there be in the tank at the end of 1 hour?

Research and discuss the aurora borealis in terms of electric charges, magnetic fields, and forces. which times of the year are best for seeing the northern lights, and where are the best places to view them? explain your answers. also identify links to good images. if you’ve ever seen the aurora borealis, describe your experience and note the time and place that you saw it.