static electricity

metals are good conductors

insulators glass cloth plastics

electrostatic charge can build up as the fuel flows through the refuelling pipe.This could cause a spark and trigger an explosion

when rubbing cloth onto plastic the plastic loses electrons transferring it to the cloth and making the cloth have positive electrons and the plastic having negative electrons on it

electrons pass from the top plastic roller onto the belt

electrons are then passed off the belt and are transferred to earth

top region of the generator becomes positive

dome on top acts as a store of positive charge

for example when someone touches the van de Graaff generator the hairs on the head become positive as a result they repel each other

For example an aircraft being fuelled:

electrostatic charge can build up as the fuel flows through the refuelling pipe.This could cause a spark and trigger an explosion.

To prevent an explosion both refuelling truck and aeroplane are earthed This prevents any charges from building up and leading to a spark