In an experiment two identical rocks are simultaneously thrown from the edge of a cliff a distance to above the ground. Rock A is thrown vertically upward with speed vo and rock B is thrown vertically downward with speed vo. Rock A and rock B strike the ground at times, and f, respectively. Consider the positive vertical direction to be upward. (a) On the axes given below, sketch and label graphs of the velocity as a function of time for rock A and rock Label the time fg. Times A and are given on the graph. Velocity Time (b) Rock B hits the ground at time fg. Derive an equation for the time it takes rock A to hit the ground in terms of vo. lg. and physical constants, as appropriate.