I don't understand these concepts from this Electrostatics lab?

Question

First: In the early days of the internal combustion engine there were a few disatrous gasoline-delivery truck explsions. After these, gasoline-delivery trucks were equipped with chains that dragged on the road. What was the purpose of these chains?

Part 3-
Basically, we were using Coulomb's law and Cheerios or paper bits with a Van de Graaff generator.

Why do the Cheerios fly up when the Van de Graaff generator is turned on (they are placed on the dome)?

Part 5-
The wings of many airplanes are equipped with metal points that face back-ward. What is the purpose of these points?

Part 6-
Using a fluorescent lamp and a Van de Graaff generator.

1) Why does the fluorescent lamp glow when placed near the generator?

2) Why does the tube not glow as brightly when positioned tangential to the surface of the dome?

Answer 1

Any moving object generates a static charge, For example water flowing through a hose pipe generates static charge, fuel flowing through the filler hose at a gas station generates a static charge, when a motor vehicle is moving along a road, static charge builds up on the body of the vehicle through dust particles in the air brushing past the vehicles body, and static charge builds up via the tyres in contact with the road. It is because of the large size of the charge build up on a cars body that you sometimes experience a zap when stepping out of the car. When you step onto the road your body will acquire the roads charge, when you then touch the metal of the car, the cars charge discharges to the earth through you via your hands and your feet. The way to stop feeling the zap is to grab the metal of the car first before you step onto the road, you then acquire the car's charge first then the charge will be discharged to the earth through your feet when you step onto the road but you won't feel it.

For the same reason, trucks were fitted with chains, as the truck travelled along the road picking up a charge from the road, the chains dragging along the road were discharging the trucks charge immediately back to the earth through the chains touching the road. So no dangerous build up of static on the truck. Modern cars are sometimes equiped with a little dragging rubber strip behind one of the rear wheels...have a look sometime....this strip does the same thing as the chains used to on the trucks.

The cheerios one I'm not sure about that one, they are probably all picking up the charge of the Generator at the same time meaning they are all the same charge, like charges repel so they are being repelled.

The wings question is one I can answer as I'm an Aircraft Engineer....those metal tabs you see are for static discharge through aircraft flight. Just as in a car, an aircraft will pick up large amounts of static charge as it flies through the air, the difference is that an aircraft has no way to touch the ground during flight....without dragging a verrrry long chain under it....LOL...however, as a passenger you don't ever get a zap when you get off the flight....why is that...? Well as the aircraft flies along picking up a large static charge, it accumulates all over the aircrafts skin including the wings....the air itself hold charge because as I explained at the beginning, all moving things including air (actualy the dust in the air not the air itself)..pick up static charge...during its flight these tabs will touch points in the air at differing voltage levels and the aircraft will discharge through these tabs to the air...water droplets in the air also have charge....so the aircraft continually charges and discharges its static charge to the atmosphere's charged particles throughout its flight.

A Flouro Lamp is full of gas which can get excited and permit the flow of electrons through it when the exciting charge gets to a certain level. Flouro's have a charging capacitor called a starter for this reason. However you can still make the gas excited by passing the tube through a charged area which charges the tube and then the gas, try getting a Flouro tube and putting it near a mains substation transformer...it will glow...because the area around the transformer will be electromagnetically charged....in the same way when you pass the Flouro near the generator it picks up the charge of the generator exciting the gas via the tube.

The tube won't glow as brightly when stood tangentially because much less of the gas is being excited...you need the whole tube of gas excited not just one little bit of it....


I know this is a long winded explanation..I hope it helps.....got writers cramp now....LOL.....good question.....

Answer 2

All of the questions have to do with an object being exposed to a magnetic field.

As the object passes through the flux, current is generated. The charge created will build up in the object unless it is shunt to ground, or an opposing current causes the charge to be dissipated.

Trucks are made of ferrous materials and have highly insulating rubber tires. When the gasoline truck moves around through the Earth's magnetic field it builds up a charge. The charge voltage can be quite high with respect to the ground, so when the nozzle of with gasoline got close enough to arc, boom. The chains shunt the charge to ground.

Fluorescent lights have a gas that is excited by voltage gradients. Model the electric field of the generator for your answer.

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