want to know if my answer is correct:

Question

anonymous · Answer

attachment

anonymous · Answer

i got 1709j

anonymous · Answer

the method i used was:
find COM
use mgh to find work done

anonymous · Answer

However, i assumed the object stopped at 37 degrees which doesn't seem to be clear from the question

anonymous · Answer

is it ok if i post a second question here?

surry99 · Answer

Can you solve in a different manner and compare the answers?

vincent-lyon.fr · Answer

Quote: the method i used was: find COM use mgh to find work done

This method is correct, but it is a bit tedious to find the common centre of mass.
Remember that potential energies add up.
So working out changes in PE for disc, and for rod separately is ok and easier.

Now, "rotating at a constant angular velocity" is a simple way to say that KE is constant and does not need to be taken into account.

anonymous · Answer

does that apply even if the object was rest initially?

vincent-lyon.fr · Answer

Yes, because it can be assumed that you can move it as slowly as you want, keeping the KE almost zero all the way.