Final answer:
To determine the tension in the horizontal massless cable CD, we can use the concept of equilibrium of forces.
Step-by-step explanation:
To determine the tension in the horizontal massless cable CD, we can use the concept of equilibrium of forces. Since the traffic light is in equilibrium, the sum of the horizontal forces and the sum of the vertical forces acting on it must be zero.
Considering the free-body diagram of the traffic light, we can see that the tension in the cable CD is equal to the horizontal component of the tension in the vertical cable AC. Therefore, the tension in cable CD is equal to the tension in cable AC multiplied by the cosine of the angle between cable AC and the horizontal.
Using the given data, we have:
Tension in cable CD = Tension in cable AC * cos(angle)