Draw the shear and moment diagrams for the beam (a) in terms of the parameters shown; (b)set P=800..

Problem statement: Draw the shear and moment diagrams for the beam (a) in terms of the parameters shown; (b) set P = 800 lbs, a = 5 ft, L = 12 ft.

[yigitcan]

Hi professor I have a question here.At interval a < x < L-a, why there's constant moment ?I mean it must be, I guess

[hotlikesauce]

At around 10:50, why is P and X-A positive if its creating a clockwise moment while P and X goes counterclockwise and create a negative moment?

[wasiullahlalzai]

isnt moment diagram graph should be linear line instead of curve? this isnt rectangular load therefore it should be linear ?