a scuba diver is exploring at an elevation of -12.2 meters. as the diver rises to the surface he plans to stop and rest briefly at a reef that has and elevation of -4.55 meters. find the vertical distance that the dive will travel

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters