Fireworks do it. But do you realize that you can also create a huge boom in the privacy of your own living room?
Things Required:
Corrugated cardboard (from a shipping box)
Pair of scissors
Brown paper
Pair of scissors
Ruler
Tape
Directions:
Cut out a triangle from brown paper. The triangle should measure 14 inches × 14 inches × 20 inches. Cut a square of corrugated cardboard. The square should measure 12 inches on a side. Use your scissors to score a straight line from one corner to the opposite corner of the square. Make sure you only score the surface and do not cut completely through the cardboard. Place the brown paper on a flat surface. Place the cardboard over it as shown in the illustration (with scored-side up). Fold over the edge of the brown paper and secure it to the cardboard with tape. Pick up this clapper device. Fold it away from the score line so that the paper may fold inside the closed cardboard halves. Hold the free end of the clapper overhead. Fling your arm down as fast as possible. What do you hear?
This Is What Happens:
As your arm dropped, the clapper opened. Air that rushed in to fill the opening space moved fast enough to create a shock wave. Although this boom was smaller than the shock waves made by supersonic jets yet it was formed in a similar way.
The crack of a whip is also caused by a shock wave. The whip crack breaks the sound barrier. A snap of the wrist produces a wave that travels down the whip. As the wave moves, it increases in speed. By the time it reaches the tip, it is travelling faster than the speed of sound. This creates a shock wave that we hear as the whip crack.
