Question $5$: $($recommended time $-20$ minutes$)$

Determine the unstretched legnth of $DB$ to hold the $40-kg$ crate in the position shown below. Consider the spring constant as $k=180\frac{N}{m}.$ Answer by following steps a to $b,$ below.

a$)$ Draw the FBD of a point that the unknown forces are passing through that point.

Write down the equilibrium equations for the above FBD and solve for the unknowns.