The motion of a mass on a spring, with spring constant \( K \) is as shown in figure.
The equation of motion is given by \( x(t) = A \sin \omega t + B \cos \omega t \) with \( \omega = \sqrt{\dfrac{K}{m}} \). Suppose that at time \( t = 0 \), the position of mass is \( x(0) \) and velocity \( v(0) \), then its displacement can also be represented as \( x(t) = C \cos( \omega t - \phi) \), where \( C \) and \( \phi \) are:
