Homework check - Mohr's circle & Shear stress in I beam

[ridiculoid]

Homework Statement

Mohrs circle question - https://imgur.com/SKeTUXN

Shear stress in I beam question - https://imgur.com/34yTyCA

Homework Equations

Mohrs Circle - None

Shear stress in I beam - I = d . b^3 / 12
tmax = (F / I . b) . (A1 . y1) + (A2 . y2)

The Attempt at a Solution

For the Mohr's circle question, I have drawn 2 induced loading elements (shown at the bottom of of my working) I just seem to have conflicting information from some class examples and am wondering whether I take the 78° clockwise or anticlockwise from the Y axis of the element.

Mohrs circle working - https://imgur.com/YPtVNSb

In the shear stress in an I beam question, It is asking for the maximum shear FORCE in the beam. Do I take the maximum value from the shear force diagram as shown in my working? or is the maximum shear force the 15kN at the point Load?

Shear stess in I beam working - https://imgur.com/UCAexj6

 

[haruspex]

Please split this into separate threads and post the complete question as given to you in each.