Question

A force F is applied on a uniform rod of cross-section A and a force F’ is applied on a uniform rod of cross-section 3A. What is the relation between F and F’ if the pressure on both is the same?

• A. F/F’ = 1/3
• B. F/F’ = 3
• C. F’/F = 1/3
• D. F/F’ = 1/9

Answer 1

Answer:

A. F/F’ = 1/3

Pressure on first rod (P) = F/A Pressure on the second rod (P’) = F’/3A Given; P = P’ F/A = F’/3A F/F’ = 1/3.