In this video (and article above), I solve a spring constant question similar to one you might encounter on the civil section of the FE Exam.
Question:
A long metal rod can be used as a very stiff spring. The deformation of a rod is given by the following expression:
P is the loading, L is the length of the rod, A is the cross-sectional area, and E is the modulus of elasticity. What is the spring constant, K, of the rod?
Solution:
The deflection, x, and the force, F, are related through the spring constant.
The loading and the deformation are similarly related.
Therefore, the term analogous to a spring constant for
the metal rod is:
Answer:
The correct answer is A. Please note, the key to this problem is knowing the units for each factor. Please watch the short video at the top of this post for a detailed explanation that could apply to this question as well as others like it.
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I hope you found this week’s engineering ethics question helpful. In upcoming articles, I will answer more FE Exam questions and run through more practice problems. We publish videos bi-weekly on our Pass the FE Exam YouTube Channel. Be sure to visit our page here and click the subscribe button as you’ll get expert tips and tricks – to ensure your best success – that you can’t get anywhere else. Believe me, you won’t want to miss a single video.
Lastly, I encourage you to ask questions in the comments of the videos or here on this page and I’ll read and respond to them in future videos. So, if there’s a specific topic you want me to cover or answer, we have you covered.
I’ll see you next week.
Anthony Fasano, P.E.
Engineering Management Institute
Author of Engineer Your Own Success
