Why do people tend to cup their hands around listeners' ears when whispering to them? a) a cupped hand makes the sound echo so the listener can hear more clearly. b) the ear cannot absorb sound waves produced by a whisper without a cupped hand. c) solid objects, such as a cupped hand, can direct sound waves into the ear of the listener. d) sound waves from a whisper are short; they will not reach the listener's ear unless guided by a hand. eliminate

Option (C) is the correct answer.

Explanation:

In solids, sound travels faster because in solids the molecules are much more closer to each other as compared to liquids and gases.

Hence, distance between molecules is the minimum in solids and sound passes from one molecule to another easily.

Thus, we can conclude that people tend to cup their hands around listeners' ears when whispering to them because solid objects, such as a cupped hand, can direct sound waves into the ear of the listener.  

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)