Where does the 500lb substitution force come from Engineerin

Where does the 500lb substitution force come from?

Engineering Mechanics Statics 13th Edition

Chapter 5, Problem 7FP

The free body diagram is W200 Ib FB 2 ft 2 ft 1.5 x3 ft Comment Step 2 of 5 Apply force balance about z axis. F, +F +Fc-W-200-0 Here, weight of the plate is W Substitute, 500 lb for Win the equation. F +FB +Fc-200+500 FA + FB + Fc =700 Comments (1) Anonymous Where does the 500lb substitution come from?

Solution

500lb is the W. he is mentioned in the solution