Question 1197038
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Hi
 The distance (d) a spring will stretch 
varies directly as the force (F) applied to the spring. 
d varies directly as F
That is:  d = kF
d = 3in when F = 12 lb
   3in= k (12lb),  {{{k = 3in/12lb = (1/4)(in/lb)}}}
find F when d = 9in 
      d = kF  0r  F = d/k
                  F = {{{9in/((1/4)(in/lb))}}} = 36 lb
Wish You the Best in your Studies.
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