📖 Explanation
Drawing the ILD of shear force just to right of Q by using Muller Breslau's principle. A cut is made just to the right of 0, since cut is very close to support Q, therefore displacement of left portion is almost zero and that to the right portion will be 1. When unit load-is at T: Vertical reaction at P and Q equal to 0 ΣM0=0
⇒1×4∴RAVO (Righit) =RR×20=0.25kN=0.25kN
Now, if moving distributed load is present over span P R then we get maximum shear force just to the right of Q . ⇒SF=[(21×0.25×10)+(21×1×20)]×4 SF=45kN