why is it safer to sit inside a bus rather than staying outside in the open space during lightning?

Question

My question is that during lightning there is a heavy discharge of electric current on the bus and due to electrostatice shielding the bus protects us but due to the heavy discharge of current the bus will get charged heavily, now where would this charges go? How would the charges flow to the earth as RUBBER tyre's are insulators

Answer 1

If you touch the metal body of the bus and lightning strikes the bus, you can be electrocuted. Cars and buses make poor Faraday cages. If you don't make contact with the metal body, the charge will be conducted around you, not through you.

If lightning strikes the bus, it will still find its way to ground despite the rubber tires. Remember that lightning is static electricity. Air does not conduct electricity but rather it is an insulator. Even though air is an insulator, lightning can reach the ground. How? Because it is a static discharge of electricity. Static electricity is not conducted through a conductor, by means of electrons hopping from one atom to the next. Instead, the electrons make one huge jump in a static spark, or with lightning.

If lighting can "jump" through the air, it can also "jump" through the rubber tires or bypass the tires all together. Lightning striking a bus will impart a huge voltage potential to the metal frame of the bus, and then lightning between the bus and the ground will discharge that voltage potential to the earth, either by lightning arcing through the tires or arcing through the air.

However, if you're in a bus or car and lightning strikes the ground near the bus, the rubber tires do help. That is because the ground is a much better conductor of electricity than rubber is. The electricity is conducted through the ground, and since rubber is a good insulator, the electricity will go through the path of least resistance.

Answer 2

Yes, there could be some charge left on the bus, conceivably. However, one thing that could very well happen is that the lightning could burn a hole through the tires into the ground. This would allow direct connection to the ground, and minimize the charge left on the bus. If the tires survive, the greatest part of the charge will still be able to jump the short distance between the bus' body and the ground-- through the air gap. The voltage required for this to happen is much higher than for direct conduction, so there would still be a substantial charge on the bus, but still much smaller than the charge that would be there if the whole lightning bolt was stuck on the bus. Even though there is a good sized charge on the bus, it's still safe to be inside because charge sits on the outside of a conductor, and won't go inside.

Answer 3

In order for lightning to strike a bus it has already found a path, using the bus, to get to the ground: when the voltage is high enough many things can conduct. The reason why it is safer in the bus is because the current will mostly stay on the outer surface of the bus.

Answer 4

The capacitance of a bus is very, very small - so it cannot store very much charge for a given voltage.

That means if it is struck by lightening, the rest of the charge will have to continue to find its own way to Earth, by striking from the bus to the Earth or by a side strike elsewhere.

With perfect tyres, the bus will indeed be charged to the voltage of the strike at the end, but there will be so little charge it will not be dangerous. Your car charges up as you drive on a dry day, which is why you caan get a shock. It charges to tens or hundreds of thousands of volts, but it is not dangerous.

Answer 5

The bus also acts as a Faraday cage - effectively protecting everything inside it from electrical or electromagnetic activity outside. Even if you are touching the metal of the bus you will be OK