1. The problem statement, all variables and given/known data A 15.0-N object is oscillating in simple harmonic motion at the end of an ideal vertical spring. Its vertical position y as a function of time t is given by y(t)=4.50 cos[(19.5s−1)t−π/8] in centimeters. What is the spring constant of the spring? 2. Relevant equations y component of spring force = -k*displacement = mg k = (mg)/displacement 3. The attempt at a solution I thought the spring constant of the spring was basically (mg)/displacement. mg = 15 N, and the total displacement of the spring is 4.50*2 = 9.00 centimeters. I thought the spring constant was 15N/0.09m = 166.67 N/m.