Sound travels about 750 miles per hour. if you stand in a parking lot near a building and a sound a horn, you will hear an echo. a. suppouse it takes about 1/2 a secon to hear the echo. how far away is the building ^13? .

Since we are referring to an echo, this means that the sound has already traveled twice the distance from the source to the building. Therefore, the real time for the distance determination is only 1/4 seconds. Using this time and the given speed,
                         distance = (750 miles/h) x (1 h/3600 s) (0.25s) 
                                         = 0.052 miles