Answer:
k = 2463 N/m
Fs = 81.12 N
Lo = 47.7 mm
Step-by-step explanation:
given data:
d =2 mm
OD = 22 mm
N_2 = 8.5
from data book
A = 1783 MPa
n = 0.19
![S_[ut] = (1783)/(2^(0.19)) = 1563 MPa](https://img.qammunity.org/2020/formulas/engineering/college/ydyg3fevd3h2ocdvw2xg3t633ajfkstcdv.png)
![S_{sy] = 0.45 S_(ut) = 70.3.4 MPa](https://img.qammunity.org/2020/formulas/engineering/college/tqsaaj0brh40kgt5zo25ima8hhiqyiaioz.png)
D = OD - d = 20 mm
c = 2D/2 = 10

Na = 8.5 -1 = 7/5 turns

for solid safe use ns = 1.2
spring rate

k = 2463 N/m
solid force


Fs = 81.12 N
Free length



As Lo is less than 105.2 the spring wiill not be buckle