Similar physical observation can

be observed and Omega is increasing.

This part will increase in proportional to the square,

very rapidly increasing, slowly increasing.

Also, you can observe

the excitation parts is influenced by Omega linearly.

So, this part is dominating the response all over.

So, when this part is dominating, in other words,

when mass is controlling the vibration,

the phase this will go that.

Therefore, this has to go that.

Therefore, it's not possible to have a y.

So, y in this direction.

So, it has to be going this.

Therefore, the phase difference between y and x

tend to be going to 180 degree.