Because it is a simple harmonic vibration, the maximum displacement of the object in both positive and negative directions is the same, and the equilibrium position is in the middle of the motion range.

The displacement range of m 1 is -0.4 to 0.4, so the equilibrium position is y = 0；;

The displacement range of m2 is -0.5 to 0.5, so the equilibrium position is also y = 0；;

The intersection of all straight lines in the image with y=0.0 is the position where the object passes through the balance.

As can be seen from the figure, the vibration period of m 1 is 5 seconds, and that of m2 is 7 seconds.

According to T=2π√(m/k), k 1 and k2 can be calculated.

M 1 vibration equation: y = 0.4 inch (2π/5t+π/5)

M2 vibration equation: y=0.5sin(2π/7t-π/2)