If a source of sound waves is rapidly approaching a person, the sound heard by the person appears to have a. a frequency higher than the original frequency. b. a pitch lower than the original pitch. c. a period higher than the original period. d. an amplitude lower than the original amplitude.

Abaseball is thrown from the outfield toward the catcher. when the ball reaches its highest point, which statement is true? (a)its velocity is not zero, but its acceleration is zero. (b) its velocity and its acceleration are both zero. (c) its velocity is perpendicular to its acceleration. (d) its acceleration depends on the angle at which the ball was thrown. (e) none of the above statements are true.