Procedure(s): make the string all lower case (use a string method called lower) note that you will have to assign the output to a variable. You can use a variable name like temp_string remove all punctuation from the string (use your new function remove_punctuation) this can also assign out to temp_string split the string into words (look for and use a string method called split) note that split will return a list of strings. Assign this as out_list return out_list g

3.12: the speed of sound the speed of sound depends on the material the sound is passing through. below is the approximate speed of sound (in feet per second) for air, water and steel: air: 1,100 feet per second water: 4,900 feet per second steel: 16,400 feet per second write a program class the speed of sound that asks the user to enter “air”, “water”, or “steel”, and the distance that a sound wave will travel in the medium. the program should then display the amount of time it will take. you can calculate the amount of time it takes sound to travel in air with the following formula: time = distance/1,100 you can calculate the amount of time it takes sound to travel in water with the following formula: time = distance/4,900 you can calculate the amount of time it takes sound to travel in steel with the following formula: time = distance/16,400