Problem 5-57 Translational Equil.- Part 4 - B

A sign outside a hair stylist's shop is suspended by two wires. The force of gravity on the sign has a magnitude of 55.7N. If the angles between the wires and the horizontal are as shown in the figure, determine the magnitude of the tensions in the two wires.
[Ans. T1=49.9N; T2=40.8N]

Diagram of sign suspended by two wires.


Accumulated Solution

Diagram of vectors with all directions and angles indicated.

a=0Fx=0,Fy=0


Correct!
In fact both (B) and (C) are correct

(B) F=0

(C) Fx=0,   Fy=0

It is (C) which is most useful and will be used here (and in most cases).

Let us look at the x-component first.

The x-components of the forces T1, T2 and 55.7N are:

(A)   T1x=T1cos45;T2x=T2cos30;0

(B)   T1x=T1cos45;T2x=T2cos30;0

(C)   T1x=T1cos45;T2x=T2cos30;0

(D)   T1x=T1cos45;T2x=T2cos30;0