Okay I have part of this problem right but am not sure how to proceed on the last part. A 50 g spring is made from a new steel/titanium alloy. Engineers determine that if a 500 g mass is hung from the spring it oscillates with a period of exactly 1.00 seconds. What is the spring's constant? Equation used is = system mass = hanging mass + (1/3) spring mass system mass = 500 + (1/3)50 = 516.6666667 Now I have to use the equation Period^2 = 4pi^2 system mass/spring constant. I have to solve for mass and don't know how to turn this last equation around.