According to Hooke's law, a 30-N force stretches a spring by 0.73 m if the spring constant k is such that
30 N = k (0.73 m)
k = (30 N) / (0.73 m)
k ≈ 4.1 N/m
Hello, seems like you've posted stuff incorrectly.
Please update the question so we can better assist you.
Surface runoff happens when, usually a liquid, flows from a high point to a low point because of a driving force in pressure difference as evident in the difference in elevation. In other words, liquid will runoff from the mountains to the plains. Since a low, flat plain has no difference in elevation, it will not cause the fluid to flow. Thus, it is impossible for surface runoff to happen within a low, flat plain.