6 questions abt differential equations and their applications

Question 7 (3 points) If the rate of change in the number of cows, W, in a population is proportional to 150 - W(t), where t is measured in years. Write the differential equation to solve for W(t]. Do not solve. Question 8 (3 points] If the temperature of an oven Olt], decreases with a rate that is inversely proportional to the temperature of the oven, write the differential equation that describes the rate of change of the oven temperature, given time, t. Do not solve. Question 9 (3 points) If the rate of change in the microwave rays Mlxl, where x is the distance, decreases with a rate that is inversely proportional to the square of the number of microwave rays, write the differential equation that describes the rate of change of the oven temperature, given a distance, x. Do not solve. l l Question 10 (3 points] If the rate of change of Q is inversely proportional to Q where Q > D. If Q00] = 250, and Q(2) = 100, Find k, the proportionality constant. Question 11 (3 points) If the rate of change of N is proportional to (10 + N), where N > -10. If N(0) = 4, and N(2) = 15, find N(5).Question 12 (3 points) If the rate of change of N is inversely proportional to sec(x). N where ( -