Question

Which statement(s) is/are TRUE with respect to the picture shown below. 

• A. A and B need to be strong in tension, and C and E in compression.
• B. C needs to be strong in tension, and A and D in compression.
• C. C and D need to be strong in tension.
• D. B needs to be strong in compression, and all others need to be strong in tension.

Hint:

Membranes and cables carry tension only; slender legs or struts primarily carry compression. When unsure, ask: would it go slack (tension) or buckle (compression)?

Answer 1

The Correct Option is C, D

Fishing wire (C): A line carries load only in tension; it buckles instantly in compression ⇒ must be strong in tension.
Umbrella fabric (D): The canopy works as a membrane in tension stretched by ribs; fabric does not carry compression ⇒ must be strong in tension.
Stool members (A, B): Primary load path in a stool puts legs in compression and rungs in mixed states; (A) and (B) misclassify C or D as compression. Statement (D) correctly identifies B as compression–critical while others predominantly need tension capacity.
Thus the true statements are \(\boxed{(C),(D)}\).