1. The problem statement, all variables and given/known data In an experiment an individual throws a rock with an initial horizontal velocity of v0 = 20 ft/s at time t=0. The rock is thrown from the edge of a cliff (directly above the base of the cliff) at height h=50 ft from the ground. The origin is assigned at the base of the cliff. Determine the magnitude of the time rate of change of the angular momentum of the rock about O (H'O) at time t = 1 second 2. Relevant equations HO = rXmv H'O = MO 3. The attempt at a solution I think that r = 50 ft j But how do I find the force from the given velocity? Any help would be appreciated.