(Solved): 4) A timber beam is being designed with supports and loads as shown. (a) Using singularity functio ...

4) A timber beam is being designed with supports and loads as shown. (a) Using singularity functions, find the magnitude and location of the maximum bending moment in the beam. (b) Knowing that the available stock consists of beams with an allowable normal stress of 12 MPa and a rectangular cross section of $$30?\mathrm{mm}$$ width and depth $$\mathrm{h}$$ varying from $$80\mathrm{mm}$$ to $$160\mathrm{mm}$$ in 10-mm increments, determine the most economical cross section that can be used.