Please I need help with this practice questions for my exam.

The population of a southern city follows the exponential law. Use this information to answer parts a and b. A pizza pan is removed at 5:00 PM from an oven whose temperature is fixed at 425 F into a room that is a (a) If N is the population of the city and t is the time in years, express N as a function of t. constant 71"F. After 5 minutes, the pizza pan is at 300 F. a) At what time is the temperature of the pan 130 F? N(t) = Nge kt b) Determine the time that needs to elapse before the pan is 170. (Type an expression using t as the variable and in terms of e ) (c) What do you notice about the temperature as time passes? (b) If the population doubled in size over 15 months and the current population is 20,000, what will the population be 4 years from now? (a) The temperature of the pan is 130OF at |PM. The population will be approximately | | people. Do not round until the final answer. Then round to the nearest minute as needed.) (Do not round until the final answer. Then round to the nearest whole number as needed.) A thermometer reading 9"C is brought into a room with a constant temperature of 36"C. If the thermometer reads 13"C after 2 minutes, what will it read after being in the room for 4 minutes? For 9 minutes? Under certain water conditions, the free chlorine (hypochlorous acid, HOCI) in a swimming pool decomposes according to the law of uninhibited decay. After shocking a pool, the pool boy, Geoff, tested the water and found the After 4 minutes, the thermometer will read c. amount of free chlorine to be 2.8 parts per million (ppm). Twenty-four hours later, Geoff tested the water again and found the amount of free chlorine to be 2.3 ppm. What will be the reading after 2 days (that is, 48 hours)? When the (Do not round until the final answer. Then round to the nearest hundredth as needed.) chlorine level reaches 1.0 ppm, Geoff must shock the pool again. How long can Geoff go before he must shock the pool again? After 2 days, or 48 hours, the amount of free chlorine in the pool will be ppm. (Do not round until the final answer. Then round to the nearest hundredth as needed.) Reacting with water in an acidic solution at a particular temperature, compound A decomposes into compounds B and C according to the law of uninhibited decay. An initial amount of 0.50 M of compound A decomposes to 0.47 M After the release of radioactive material into the atmosphere from a nuclear power plant in a country in 1997, the hay in that country was contaminated by a radioactive isotope (half-life 7 days). If it is safe to feed the hay to cows in 30 minutes. How much of compound A will remain after 2 hours? How long will it take until 0.10 M of compound when 14% of the radioactive isotope remains, how long did the farmers need to wait to use this hay? A remains? After 2 hours, the amount of compound A remaining will be | M. The farmers needed to wait approximately | days for it to be safe to feed the hay to the cows. (Round to one decimal place as needed.) Do not round until the final answer. Then round to the nearest hundredth as needed.)