I feel like an idiot for not being able to answer this question, it seemed so simple yet so complicated in my head. 1. The problem statement, all variables and given/known data Have to find frequency, given the amplitude, velocity, and mass. I don't have numbers as it was off an exam I just took. Guessing it was v=5 m/s; A=10m; and m=3kg. 2. Relevant equations I was thinking of taking the derivative of the SHM eq x(t) = Asin(wt) but then I wasn't sure if I could calculate the spring constant with F = -K(xo - xf). 3. The attempt at a solution My attempt was guessing, but if we threw in numbers, A=10m, v=5m/s, m=3kg... x(t) = A * sin(wt) w = 2 * PI * f x(t) = A * sin(2 * PI * f * t) v(t) = 2 * PI * f * A * cos(2 * PI * f * t) t = 0 5 = 2 * PI * f * 10 * cos(2 * PI * f * 0) 5 = 2 * PI * f * 10 * 1 5 = 20 * PI * f 5 / (20 * PI) = f f = 0.0795Hz or.. F=-K(x-xo) F = 3*9.8 = 29.4 x = 10 xo = 0 K = 2.94 N/m f = (1 /( 2 * PI )) * sqrt( k / m) f = 0.159 * sqrt (2.94 / 3 ) f = 0.1576 Hz Would love to know the correct way to do this, as I'm confused..