Anewly constructed fish pond contains 2000 liters of water. unfortunately, the pond has been contaminated with 5 kg of a toxic chemical during the construction process. the pond's filtering system removes water from the poind at a rate of 200 liters/minute, removes 10% of the chemical, and returns the same volume of (the now somewhat less contaminated) water to the pond. write a differential equation for the time (measured inminutes) evolution of: a) the total mass (in kilograms) of the chemical in the pond: dm/dt =

b) the concentration (in kg/liter) of the chemical in the pond: dc/dt =

c) the concentration (in grams/liter) of the chemical in the pond: dc/dt =

d) the concentration (in grams/liter) of the chemical in the pond, but with time measured in hours: dc/dt =