The pH scale is used to tell if a substance is an acid or base. Substances with a pH
of 7 are neutral. An acid is anything
below 7 and a base is anything above
7.What would a household cleaner with a
pH of 10 be considered on the pH scale?
A. base
B. acid
C. neutral

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.