Final answer:
To determine the tension in the cable supporting a bar with an attached post, we use the equilibrium condition of the system. The tension is calculated by subtracting the post's weight from the bar's weight, resulting in a tension of 750 N.
Step-by-step explanation:
The question is about finding the tension in the cable that supports a bar AB with an attached post CD. To determine this, we must consider the forces acting on the system and ensure that the sum of the vertical forces equals zero since the system is in static equilibrium. The bar AB weighs 1000 N, and it is supported by the post CD weighing 250 N and the cable. Assuming the post and the cable provide the only vertical support forces, this would mean that the cable must support the weight of the bar minus the support contributed by the post weight (if we assume the post acts vertically).
To calculate the tension in the cable (T), use the following balance equation:
T + weight of the post = weight of the bar
T + 250 N = 1000 N
T = 1000 N - 250 N
T = 750 N
So, the tension in the cable is 750 N. As a result, the correct answer is option (c) 750 N.