Two springs with equal spring constants k are connected first in series (one after the other) and then in parallel (side by side) with a weight hanging from the bottom of the combination. What is the effective spring constant of the two different arrangements? In other words, what would be the spring constant of a single spring that would behave exactly as
(a) The series combination and

(b) The parallel combination? Ignore the weight of the springs. [For (a): each spring stretches an amount x = F / k, but only one spring exerts a force on the hanging object. for (b): each spring exerts a force F = kx.]