Taking Moments Propped Cantilever

[christian Bendis]

Hello all

I was hoping someone could shed some light on the following question:-

I have a propped cantilever beam as shown below:-

Question.png


I want to work out the vertical reactions at support A and B.

I have been told to work out the vertical reactions I need to take moments about support B and by doing so the reactions at support B "disappear" - my question is if I take moments about support B do ALL of the reactions disappear and if not which ones remain and which ones disappear?

I hope this makes sense.

Thank you.

[Kelly_Bramble]

See:

https://www.engineersedge.com/beam_b..._bending17.htm