M2 question :(

How can I do 5 ii ?

Label the diagram a bit more - include dots where appropriate to represent the centre of mass for each part of the rod. Secondly, measure out their distances along their respectively parts. Furthermore, the wire is uniform, so it has the same density throughout which you can call $\mu$. Then the mass of each part of the rod is just $m=\mu \ell$ where $\ell$ is the length of the part.

Also, label $\angle BCD = \theta$ and so you know that $\cos \theta = \frac{4}{5}$. Use this to determine $\sin \theta$ as you'll be using these.

So then begin the question, finding the horizontal distance of the overall CoM from the point B. This is the same as finding the horizontal distance from the part AB. You have 3 different objects each with their own CoM so just determine the overall one from a formula you know.

Label the diagram a bit more - include dots where appropriate to represent the centre of mass for each part of the rod. Secondly, measure out their distances along their respectively parts. Furthermore, the wire is uniform, so it has the same density throughout which you can call $\mu$. Then the mass of each part of the rod is just $m=\mu \ell$ where $\ell$ is the length of the part.

Also, label $\angle BCD = \theta$ and so you know that $\cos \theta = \frac{4}{5}$. Use this to determine $\sin \theta$ as you'll be using these.

So then begin the question, finding the horizontal distance of the overall CoM from the point B. This is the same as finding the horizontal distance from the part AB. You have 3 different objects each with their own CoM so just determine the overall one from a formula you know.

Can you tell me why sometimes the y is ignored?

What's y?

y bar. Nm I think I know