The force a spring exerts on a body is a conservative force because: a. a spring always exerts a force parallel to the displacement of the body.
b. the work a spring does on a body is equal for compressions and extensions of equal magnitude.
c. the net work a spring does on a body is zero when the body returns to its initial position.
d. the work a spring does on a body is equal and opposite for compressions and extensions of equal magnitude.
e. a spring always exerts a force opposite to the displacement of the body.

  c.  the net work a spring does on a body is zero when the body returns to its initial position

Explanation:

A force is conservative when the net work done over any path that returns to the initial position is zero. Choice C matches that definition.

An ideal spring of the kind used in physics problems has the characteristic that it applies the same force at the same distance always. So any work required to extend or compress the spring is reversed when the reverse motion takes place.

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