Update A03.md

book/content/A03.md

@@ -184,7 +184,19 @@ Select which statement described the importance of the term in this situation th
 
 ````{admonition} Model answer a
 :class: dropdown
-The red angle $\theta_3$ represents the angle between the blue and red vectors, with angles $\theta_1=-ks+\alpha=\alpha$ and $\theta_2=-ks+\alpha$ (with respect to the real axis). So the red angle is the difference between them $\theta_3=\theta_1-\theta_2=\alpha-(-ks+\alpha)=ks$.
+Let’s choose the resistance parameter to scale all the other ones respect to it. The ratio between the local acceleration and the resistance term equals 0.18. So, it cannot be neglected. See lecture 8 for a more complete description of terms estimation.
+````
+````{admonition} Model answer b
+:class: dropdown
+The ratio advective acceleration / resistance equals 0.008, so the advective term plays a small role in this situation (compared with the resistance) and can be neglected.
+````
+````{admonition} Model answer c
+:class: dropdown
+So far, the resistance term has been larger than the local and advective term. It is missing information to compare it with the gravity term. To determine the order of the gravity term it is missing the wave height value. A typical value would be 1m, in this case the ratio gravity/resistance equals 0.22. The resistance term is the most important one, and this would remain true even for wave heights of 4m. For this case, supposing that the flow velocity remains the same, the ratio gravity/resistance would equal 0.9.
+````
+````{admonition} Model answer d
+:class: dropdown
+Following the previous answer, the gravity term is lower than the resistance but it would still play an important role in this situation.
 ````
 
 ## Question 11