(Solved): A rope suspension bridge spans a chasm that is 100 meters wide taking the shape of a catenary whose ...

A rope suspension bridge spans a chasm that is 100 meters wide taking the shape of a catenary whose curve can be modeled by the function $y=f(x)=75\cosh \left(\frac{x}{75}\right)=$ $\frac{75}{2}\left(e^{x/75}+e^{?x/75}\right)$. Dora is at the exact midpoint of the bridge when she notices Swiper cutting the ropes holding the bridge to the cliff edge behind her. If Swiper's knife is dull and Dora knows it will take him at least 10 seconds to cut completely through the ropes, how fast must Dora run (in meters per second) to ensure that she escapes the bridge safely to the other