Rotational Equilibrium (Finding tension)

[Pinkchika88]

Homework Statement

a restaurant sing hangs from a metal bar attached to a wall and supported by a wire. the bar has a mass of 5 kg, and a length of 1.2 m. the sign has a mass of 23 kg and hangs from 2 chains located at .3 m from each end of the bar. the wire makes a 28 degree angle with the bar

Homework Equations

find the tension of the wire
find the normal force the bar exerts against the building

The Attempt at a Solution

i drew the free body diagram and found that the F_weight of the bar and the F_weight of both chains should equal F_tension*cos28. is this right?

 

[member 553083]

Fweight of bar= 5g Fweight of chains= 23g*2 Ftension cos28 = Ftension*cos28 Ftension= (5g + 46g)/cos28 for normal force, i know that it should equal the Ftension*sin28. so Fnormal = Ftension*sin28 = (5g + 46g)*sin28/cos28