What is the spring constant?

Answer 1

it is a value unique for every spring and depends on the materials. it doesn't change if the characteristics of your spring don't. if we have a spring with k spring constant and cut it in 2, the resulting springs still have k spring constant.

the spring force depends on the spring constant. this formula F=k*x gives the force applied to a body by a spring, when it hase been pulled by x from it's natural state.

Answer 2

For two springs in parallel the net force is equal to the sum of the force of each spring. Let one spring have spring constant k1 and the second k2 .

Feq = keqx = (k1+k2)x

keq = k1+k2

For two springs in series, the force is applied at the end of spring 2 and the spring 1 is fixed to a wall. Spring 1 is stretched (or compressed) the distance x1 and spring 2 is stretched (compressed) x2

Basic solution: displacements

Feq = keq(x1+x2) = k2x2

and k2x2=k1x1

gives keq = k1k2 / (k1+k2)

More advanced solution: positions

Let now x1 and x2 be the displacements from points 1 and 2 which are undisturbed positions at the connection between springs 1 and 2, and at the position of the applied force respectively.

k1x1= k2(x2-x1) = keqx2

x1= k2x2/(k1+k2)

keq= k1k2/(k1+k2)

Author Ignacio E. Olivares

Answer 3

Hooke's Law can be stated as:

F = -kx

Where x is the displacement, k is some constant, and the negative sign means that the force is in a direction opposite to the displacement.

Solving for the constant k gives:

k = -F/x

In SI, this would give it units of Newton / meter, but any other convenient unit can be used, for example, Newton / centimeter.

Answer 4

Nm-1