38. A rock of mass 0.400 kg is released from the surface and sinks in the ocean. As the rock descends it is acted upon by three forces: gravity, buoyancy, and drag. The buoyancy is an upward force equal to half its weight. Drag from the water can be modeled by F = kv, where k = 0.650 kg/s. (a) Determine the terminal speed of the sinking rock. (b) Determine its depth, speed, and acceleration 1.50 seconds after it is released. (c) At what depth will it be at 99.0% of its terminal speed?

Question

38.  A rock of mass 0.400 kg is released from the surface and sinks in the ocean.  As the rock descends it is acted upon by three forces:  gravity, buoyancy, and drag.  The buoyancy is an upward force equal to half its weight.  Drag from the water can be modeled by F = kv, where k = 0.650 kg/s.  (a) Determine the terminal speed of the sinking rock.  (b) Determine its depth, speed, and acceleration 1.50 seconds after it is released.  (c) At what depth will it be at 99.0% of its terminal speed?