How Does the Principle of Superposition Apply to Forces in a Spring System?

[chandran]

step 1
i have a spring with two ends i and j. I fix i and pull j to a displacement and measure the force at i and j called fi and fj

step 2
now i fix j and pull i to a displacement and measure the force at i and j called fi and fj

principle of superposition says that the total force at i and j (Fi and Fj)is equal to

Fi=fi(step1)+fi(step2)
Fj=fj(step2)+fj(step2)

i don't understand how the forces in both the steps are added. What is the principle of superposition

is there any website ?

 

[HallsofIvy]

Clarify your terms. What is the difference between "the force at i", fi, and the "total force at i", Fi? If fi is not the "total force" how are you measuring it?