Problem $3$:

The rope CE exerts an $800$ N force $T$ on the hinged door. Let $r_{BC}$ be the vector from point B to

point C$.$

Express $T$ in terms of Cartesian components;

Determine the unit vector $n,$ which is perpendicular to the door;

Find the components of and that are parallel and perpendicular to the

door; $($Hint: determine perpendicular to the door first, and think about why?$)$

Determine the product $n*(r_{BC}T).$

Hint: perpendicular to the door also means that it is parallel to the unit vector that is

perpendicular to the door. Hope this helps.