- #1

SShep71

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- Homework Statement
- 1-3. The spring force F and displacement y for a close-wound tension spring are measured as shown in Fig. P1.3 The spring force and displacement satisfy the linear equation y=((1/k)F-(Fi/k)

, where k is the spring constant and Fi is the preload induced during manufacturing of the spring.

(a) Determine the spring constant k and the pre-load F using the given data in Fig. P1.3. (b) Sketch the graph of the line y(F) and clearly indicate both the spring constant k and preload Fi using the given data.

- Relevant Equations
- y=((1/k)F-(Fi/k))

There is some discussion currently and I was hoping to get some opinions here. The question is in regard to a Hook's law problem. The text gives the problem as seen below. The text says the answer is 50lb/in. Several people have tried from several different approaches. Factoring the "y" equation to solve for Fi, straight method, etc.

In case the image does not work, here are the specifics:

k= spring constant

Fi=preload at manufacturing

F=spring force

y=displacement

Observations:

F(lbf) y(in)

100 1.0

75 0.5

The students are to determine the "Fi" and "k" values. The book states 50lb/in as the answer

In case the image does not work, here are the specifics:

k= spring constant

Fi=preload at manufacturing

F=spring force

y=displacement

Observations:

F(lbf) y(in)

100 1.0

75 0.5

The students are to determine the "Fi" and "k" values. The book states 50lb/in as the answer