Students who enjoy firing guns can determine whether doubling the pressure within the chamber doubles the speed at which its projectile travels. Connect an air gun to an air compressor and load the chamber with pellets. Attach a sensor to a barrel to record the velocity of the pellets. Set the pressure to 100 psi and fire five rounds through the barrel. Record the speed of each round and determine the average pellet velocity at 100 psi. Double the pressure and repeat the experiment. Compare the results to see if pressure and velocity are directly proportional.
Changes in atmospheric pressure are powerful enough to cause implosions. Demonstrate this fact by rinsing out two empty soda cans. Fill a bowl with cold water and add 1 tbsp. to one soda can. Place the can on a cold stove burner and turn on the heat. Once steam begins to escape from the can's mouth, leave the can on the burner exactly 1 minute before removing with tongs. Immediately turn the can upside-down and submerge straight down in the cold water. Because the atmospheric pressure is approximately double that of the pressure in the can, the air pushes on the can with such force it will implode and crumple.
In the classic egg-in-a-bottle experiment, students observe what appears to be a magical feat. An egg is set on the mouth of a bottle and is clearly too large to drop into the bottle. The egg is removed from the mouth, and a flame source, such as match or small flaming piece of paper is dropped into the bottle. The egg is returned to the bottle's mouth. The flame requires oxygen, but quickly expends what is available in the bottle. The egg prevents additional air from entering the bottle, which creates an imbalance in the internal and external atmospheric pressures. To restore balance, the atmospheric pressure forces the egg into the bottle, eliminating the vacuum.
Students need a Boyle's law apparatus, aneroid barometer and thermometer to test whether temperature is in agreement with Boyle's law over a range in atmospheric pressure. Level the apparatus and store 6 cubic centimeters of air in a graduated tube at atmospheric pressure. Record the height of mercury in each tube. Raise the graduated tube to increase the air volume in .5-centimeter increments until the air volume reaches 12 cubic centimeters. Record the mercury height at each interval and take barometer and thermometer readings at frequent intervals. Compare the data to determine the percentage maximum deviation between the temperature and atmospheric pressure readings.