To find the tension in the rope making a
30° angle with the vertical, we can use the equilibrium conditions for the
sign. The vertical forces must balance the weight of the sign.
Given:
Weight of the sign () = 120 N
Tension in the first rope () at 30° to
the vertical
Tension in the second rope () at 60°
to the vertical
Step 1: Resolve the tensions into vertical
components
The vertical components of the tensions can
be expressed as follows:
1. For (30°):
2. For (60°):
Step 2: Write the equilibrium equation for
the vertical forces
The sum of the vertical components must
equal the weight of the sign:
Substituting the expressions for
and :
Step 3: Resolve the horizontal components
Since the system is in equilibrium, the
horizontal components must also balance out:
Where:
1. For :
2. For :