the amount of water, A, in thousands of liters, available in a water tank located on a farm fluctuates in a yearly cycle and can be modeled by the function. A(t)=asin(kt)+b where t is the elapsed time, in weeks, since the start of the year. The amount of water available in thank on week 6 is 24 thousand liters and on week 31 is 9.2 thousand litres. Find the value of k, in degrees, assuming there are 52 whole weeks in a year.