1/25/10
Science, period 7
What could be worse than having your home destroyed by a natural disaster? When a tornado strikes, some homes are destroyed and others are not. Some of these homes appear to have been torn apart from the inside, as shown below. Some homeowners think the low air pressure of the storm outside, may have caused their homes to explode. One myth is that if you crack a window during a tornado, the air pressure will equalize and prevent damage to your house.
(Left: A house whose front wall and Roof were torn off by a tornado in Stillwater, NY. (Lewison))
The force exerted by a column of air is defined as air pressure. As the concentration of air molecules in the atmosphere changes, so does the pressure. Pressure can be measured using a barometer and is measured in units called millibars. The energy of a storm is greatly affected by the speed of the wind, and the air pressure influences this. A tornado forms in an area of low air pressure (Netting).
The myth that cracking a window during can prevent a house from imploding or exploding from air pressure changes is false. A tornado is more than simply a phenomenon of air pressure. Tornadoes produce wind of at least from 30 to 70 miles per hour, which alone cause heavy damage to homes (Are You Ready?"). Observations have shown that it is these high-speed winds that lift the roof and cause damage, not pressure (Mikkelson and Mikkelson). The Kinetic Energy held by the moving winds can be shown by the formula KE=1/2MV^2. In this formula, M represents the Mass, or density and V is the velocity of the moving object. Since the force applied by the wind is directly proportional to its pressure, but equal to its velocity squared, the speed of the wind has a greater effect on its energy and force. Therefore, to protect your home better, you should try to keep it as airtight as possible, as leaving a window cracked will only allow more damaging wind into your home (Mikkelson and Mikkelson).
Works Cited
“Approaching Storms.” The National Hurricane Initiative. Ron Sachs Communications, 2009. Web. 29 Jan. 2010.
“Are You Ready? Tornadoes.” FEMA. N.p., 4 June 2009. Web. 29 Jan. 2010.
Lewison, Dave. Further north on Rte. 4, this house had its front wall blown out and its roof torn off. This house was directly on the shore of the Hudson River facing east. 31 May 1998. facethewind.com. N.p., n.d. Web. 29 Jan. 2010.
Mikkelson, David P, and Barbara Mikkelson. “Hurricane Mutiny.” Snopes.com. N.p., 30 Aug. 2005. Web. 29 Jan. 2010.
Netting, Ruth. “Its a Breeze: How air Pressure affects you.” Kids Earth Science Enterprise. NASA, 26 Oct. 2004. Web. 29 Jan. 2010.
Ritter, Michael E. “Air Pressure Pressure variations across the Earth.” he Physical Environment: an Introduction to Physical Geography. N.p., 1 Oct. 2009. Web. 29 Jan. 2010.
