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Dangers of Electrostatics
Transcript of Dangers of Electrostatics
Electrostatic is the term used for slow-moving or stationary electric charges. Charges are known to have the ability to 'jump' through the air, just like lightning but usually on a smaller scale. Although it may be on a smaller scale, these jumps can too be extremely dangerous in certain situations.
Dangers of Electrostatics
Build up of Charge
Static charge build up happens from one of two processes. Friction of substances together or by proximity to an electrostatic field (induction charging).
What is the danger?
The main dangers of electrostatic revolve around sparks. Sparks can ignite flammable objects and cause fires and explosions. Even small amounts of heat can destroy a once perfect piece of equipment.
The main examples would include: Filling an aircraft or car with fuel, and using any valuable electronic equipment. Whilst filling an aircraft with fuel (an insulator), if charge builds up in the fuel due to friction then a spark may fly, filled with electrons looking to fill an object. But since kerosene is very flammable then a huge explosion is on the cards. With electronic equipment, a similar event can happen. When two objects approach each other, and one has a strong opposite charge, then a spark may jump, causing damage to the equipment.
That doesn't sound good. How can I stop that?
This build up of static charge can only occur in an object where the charge can flow to earth, so usually insulators. But you can connect anything to earth, allowing the charges to disperse. So attaching a cable from earth to the object would ensure no dangerous amounts of charge builds up. Scientists have made anti-static shoes and wristbands to make their equipment and themselves safe.
The Jump to Hyperspace
When large amounts of electrostatic charge build up within an object it suddenly can become a problem. As you (should) know opposite charges attract and the same charges repel. Electrostatic discharge occurs when two objects with different charges or a different amount of electrons face each other. What is now dangerous, is if a spark jumps through the air, which could ignite nearby flammable substances. The spark jumps so it can reach an object of an opposite or neutral charge.
Electrostatic charges are formed because of friction or induction, and can be dangerous because of sparks. Sparks jump from one substance to another as it's attracted to a substance of a neutral or opposite charge to it's previous, charged, object. These sparks can cause a great deal of danger so safety precautions should be made. We should respect and fear the awesome power of electrostatic charges. Thank you electrostatic charges. Thank you.
By Alfie, Ricky & Tom
For a static electric charge to occur at least one of the substances must be an insulator, which makes it harder for protons and electrons to move. Static electricity is formed when positive and negative charges are separated. Electrons can be swapped between materials on contact. Materials with weakly bound electrons usually lose them whereas materials with very full outer shells tend to gain them. This is known as the triboelectric effect. It's sounds complicated but really, it's extremely complicated.
At the mouth of the Catatumbo River in Venezuela, lightning flashes almost continuously for around 200 nights every year. Methane rising from marshes and nearby oil deposits is thought to play a key role in this process.
Scientists are not sure how the charges of clouds come to be but it is clear that the separation of +ve and -ve charges takes place, and that ice must be present. Negative charges tend to collect at the bottom of a cloud. Negative charges move down to the ground in 'steps of 50 to 100 meters and are called stepped leaders. In response to this discharge, positive charges move upwards in whats called an upward leader. When the two meet, usually at around 30 to 100 meters above ground, a luminous electric current shoots up to the cloud. Since opposites attract, the closer (higher) an object of a -ve or neutral charge is to a cloud with a high -ve charge on the bottom, the more likely it is to be struck.
Obviously this isn't very safe. At extremely high voltage, being hit by a lightning bolt can easily kill a human, or easily start a fire. Both of these would not be ideal. Since skyscrapers are higher up they tend to be hit more often and are more likely to be hit. To prevent major damage architects use techniques like adding earth wires so that the charges can disperse themselves amongst a wide area, or making everything sturdy or doing something complicated with weird names like downconducting shielding.