Rule $1$: Concentrated forces cause a jump $($i$.$e$.,$a discontinuity$)$ in the shear diagram at the location of the force. The jump is in the same direction as the concentrated force arrow.

Try One

Determine the internal shear force $V($in $kN)$ that exists in the beam at the following locations:

$x=4m,$

$v=,kN$

$x=6\mathrm{.}5m,$

$v,$