Discharging Electrically Charged Objects Discharging Many everyday activities
Discharging Electrically Charged Objects
Discharging… • Many everyday activities that we take for granted can generate electrical charge: – Gas pumping through a hose – An airplane flying • In either example, a static charge could be very dangerous. If it was allowed to build up, it could ignite the gas or interfere with the plane’s computer system • When an excess charge is removed, it is said to have been discharged or neutralized
Grounding • The easiest way to discharge an object is to connect it to the Earth with a conductor • When this happens, the object is said to be grounded – it shares its charge with the Earth • Examples: – Gas pumps & hoses – Assembly line workers who put together computers, appliances and so on – Astronauts are ‘grounded’ to their spaceship
Grounding Via Lightning Rods
Discharge at a Point • Grounding won’t always work – imagine trying to ground an airplane! • Airplanes make use of how charges behave on the surface of conductors • The shape of a conductor will affect how quickly it will discharge – Rounded objects hold charge better because they spread it out more evenly
Discharge at a Point • Pointed conductors lose charges at the end of the point as the repelling force between the electrons pushes electrons off the conductor – Discharge at a Point
Static Wicks • Airplanes use conductors that come to a point at one end (called Static Wicks) to discharge the plane in flight
Discharging in Other Ways 1. Humidity – water molecules in humid air (like a muggy summer day) draw the static charge out 2. Light – light particles (photons) knock electrons off of the object 3. Radioactivity – radioactive emission neutralizes electrons
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