$|-$Neglecting the beam mass, complete Example $5\mathrm{.}1!!!-|$

Draw the free$-$body diagram of the uniform beam shown in Fig. $5-7$a$.$ The

beam has a mass of $100$ kg $.$

Fig. $5-7$

$($a$)$

Effect of fixed

support acting

on beam

$($b$)$

The free$-$body diagram of the beam is shown in Fig. $5-7$b$.$ Since the support

at $A$ is fixed, the wall exerts three reactions on the beam, denoted as $A_x,A_y,$

and $M_A.$ The magnitudes of these reactions are unknown, and their sense has

been assumed. The weight of the beam, $W=100(9\mathrm{.}81)N=981N,$ acts

through the beam's center of gravity $G,$ which is $3$ m from A since the beam is

uniform.