Situation $7.$ The double angle shown in the figure carries a tensile force of P$.$ Given:

Allowable shearing stress of bolt $=150$MPa

Allowable tensile stress of bolt $=195$MPa

Bolt diameter, $D_1=D_2=25mm$

$a=4,b=3$

$19.$ Find the maximum safe load $P($kN$)$ based on tensile and shearing strength of bolt $D_2.$

A$.638$

C$.524$

B$.425$

D$.368$

$20.$ Find the $P(kN)$ based in shear strength of bolt $D_1.$

A$.491$

C$.451$

B$.441$

D$.521$

$21.$ If $P=400kN,$ what is the required diameter of bolt $D_2?$

A$.28$

C$.20$

B$.25$

D$.18$