You decide to experiment to measure the speed of sound. You have a friend drop a softball at the same time he hits an air horn. If you are 150 m away from your friend and you measure 0.45 seconds between the time you see the ball drop and you hear the sound of the horn, what is your experimental value of the speed of sound?
Light travels about one million times faster than sound (in air), so you may consider the sight of the dropping of the ball to be the same instant that it really happens.
Divide the separation distance (150 m) by the time delay of the sound (0.45 s) to get the speed of sound.
You should get 333 m/s, which is about right