The internal shear force V at a certain section of an aluminum beam is positive $8$ kN $,$ as shown below. If the beam has the cross section shown:

a$.$ Determine the shear stress at point H $,$ which is located $30$ mm above the bottom surface of the tee shape. Draw a stress element in the x$-$y plane, showing the shear stress at this point. Include coordinate axes and label the stresses, showing proper direction and magnitude.

b$.$ Determine the maximum horizontal shear stress in the tee shape. Draw a stress element in the $x-y$ plane, showing the shear stress at this point. Include coordinate axes and label the stresses, showing proper direction and magnitude. Label the location of the stress element on each figure below $($or on your own sketches$).$