RE: 'Plane' crisps!
Well, back to my school days, "Air" is 4/5's Nitrogen and 1/5 other gas. Because the crisp packets expand at altitude the Nitrogen must be denser than the air outside the packet, as it can expand to fill its container. ?????? someone correct me if im wrong!!!
I stole this from the Walkers website:
"Walkers products are packaged using a Nitrogen flush to remove the oxygen from the packaging. Nitrogen helps keep the fresh flavour of the crisps by excluding oxygen and atmospheric moisture, which can cause rancid flavours and staleness. If these are excluded by nitrogen flushing, the product has the potential to stay fresh longer. The crisps are therefore, enclosed into the bag with Nitrogen to protect the product and maintain its fresh taste for longer"
Okay, so...
The air in a crisp packet on the ground is 'normal'. 🙂
The gas particles of nitrogen inside the packet are in an equilibrium state. This means that the forces acting on the bag from the inside are the same as those acting from the outside.:D
However, as you travel to higher ground (or maybe not ground in this case:p) the air pressure lowers - which is why our ears pop:rolleyes:. At higher elevations, there are fewer air molecules around.;)
This means that the particles are no longer in a state of equilibrium, and because there are more particles inside the bag than around it, the particles in the bag want to escape.o_O
They move faster, meaning they will hit the the sides of the bag more frequently.:cool:
Pressure is caused by particles hitting the sides of it's container.:eek:
So whilst many particles are repeatedly hitting the sides of the container, the bag is expanding, to be able to take the pressure.:oops:
If you go past a certain height (depending on the size of the packet of crisps:confused:) the bag of crisps you paid for is going to pop and be wasted:mad:, and when you're hungry you won't be very happy about that:(!