For sounding sirens varies by jurisdiction, so check with your local community to find out the specifics if you are interested. Sirens are an outdoor warning system designed only to alert those who are outside that something dangerous is approaching.
For alerts indoors, every home and business should have a NOAA Weather Radio All-Hazards. People should be indoors and monitoring local media for updates on the storm.
When thunderstorm winds exceed 70 mph, trees can be uprooted or snapped. Hail that is golf ball sized or larger can break windows.
Both of these things pose a direct risk to life if people are caught outdoors. An increasing number of communities (including in the Quad Cities area) are incorporating these threats into their outdoor warning siren policies.
On average, the Quad City area experiences 5 storms each year that meet the common siren guidelines. You can find information about past storms and their frequency in your community through the National Climatic Data Center.
The safest approach is to be proactive and use all the information available to protect yourself and your family from threatening weather. Sirens are only one part of a warning system that includes preparation, NOAA Weather Radio, and local media.
Why does the Quad City area have a common guideline for sounding outdoor warning sirens? If people are unsure or confused about an alert, they may not respond quickly or appropriately.
By adopting common outdoor warning system guidelines, confusion will be eliminated, response time will be reduced, and lives will be saved. Throughout the Quad City metro area, communities have adopted a common protocol for sounding their outdoor warning systems (sirens).
This difference in the sound of the siren (or the horn of a car or a train) is due to a scientific phenomenon called the Doppler Effect. Imagine driving home along a road that has a surprisingly small amount of traffic.
Before you even turn your head to see, your mind has already registered that an ambulance is approaching your position from behind. The siren sounds louder and more shrill as the ambulance approaches your car, but then changes its pitch as soon as the ambulance overtakes you, almost like an opera singer can change the shrillness of her voice.
This difference in the sound of the siren (or the horn of a car or a train) is due to a scientific phenomenon called the Doppler Effect. Our world is replete with events and daily-life experiences that are associated with Doppler effect.
Suppose you are standing on the sidewalk, waiting to cross the street. On the far left side of your position, you see an ambulance racing in your direction.
As the ambulance approaches you, the distance between the source of the waves and the observer decreases. As the ambulance moves away from you, the distance between you (the observer) and the siren (source of the sound) increases.
The same case applies to a police vehicle as it passes you by, and those loud train horns you hear approaching on the tracks. These common phenomena seem to fascinate many people, especially literary minds, who make comparisons like ‘the blaring sound of a truck horn’ or ‘the shrillness of the horn of an approaching train’.
Do these people realize that they are inadvertently entering the realm of physics when they describe these unique sounds? The Doppler effect is not just observed with horns and sirens, but also in some extremely boring events of daily life.
| WonderopolisWe sent you SMS, for complete subscription please reply. Today’s Wonder of the Day was inspired by Roberta.
One popular answer to why fire trucks are red goes something like this: “Because they have eight wheels and four people on them, and four plus eight makes twelve, and there are twelve inches in a foot, and one foot is a ruler, and Queen Elizabeth was a ruler, and Queen Elizabeth was also a ship, and the ship sailed the seas, and there were fish in the seas, and fish have fins, and the Finns fought the Russians, and the Russians are red, and fire trucks are always “Russian” around, so that's why fire trucks are red !” The real reason why fire trucks are red remains somewhat shrouded in mystery.
A competing theory dates back to the same time when fire departments were composed of unpaid volunteers. According to this other theory, however, there was fierce competition amongst the volunteer brigades of neighboring towns.
Another theory holds that fire trucks were painted red to make them stand out from all the other vehicles on the road. In the early 1900s, Ford only offered cars in black, so red fire trucks would be sure to stand out amidst the sea of black vehicles on the road.
Today, red remains by far the most popular color for fire trucks and a variety of other emergency vehicles. For example, it's not uncommon to see fire trucks that are white, yellow, blue, orange, green, and even black.
With the help of an adult friend or family member, give your home a fire safety check-up. Make sure everyone in your household knows where the exits are and what to do in case of an emergency.
Ask an adult friend or family member to take you on a field trip to a local fire station. Plan a visit and then prepare some questions in advance that you would like to ask the firemen you meet.
Now that you know a bit more about fire trucks, have you ever Wondered exactly how they work? Do some Internet research by reading through How Fire Engines Work.
Write down at least five interesting facts to share with a friend or family member. Use your imagination to develop a few possible improvements that could be made to the fire truck.