You watch distant Sally Homemaker driving nails into a front porch at a regular rate of 1 stroke per second. You hear the sound of the blows exactly synchronized with the blows you see. And then you hear one more blow after you see the hammering stop. Explain how you calculate that Sally is 340 m away from you.

Solution 5P The hammering frequency is 1 stroke per second. As the view of hammering is exactly synchronized, it reaches you in 1 second. The speed of sound in air medium is equal to 340 m/s. As we know the speed and the time, it’s not a big deal to get the distance. The formula...