Experiment Two Two weeks after the first one, another experiment. And my first thought is: isn’t this a bit dangerous? Hot water in cans that buckle and cave in? The teacher’s really got to be 100% sure his grasp of Physics is up to par, or we could be looking at a class full of maimed kids. Not that anyone would have really cared about that back then. But I’d have a hard time believing you could do this experiment with a bunch of eight year olds in 2021. Again, I’m not sure I’ve written this up in the most effective manner. Yes, I’ve described what happened, but I don’t think I quite grasped why. I mean, if the top’s on, the steam can’t escape, so surely the pressure of the steam - which wants to escape the bottle - must make it explode outwards, not buckle and implode? Got to find a way of explaining it. Maybe using another experiment on the internet will help. OK, here’s one: https://coolscienceexperimentshq.com/how-to-crush-a-bottle/ - This one uses a plastic bottle and, crucially, needs to be lying in a bed of ice, with cold water poured onto it. I expect we managed to skip this part because we were in Yorkshire in the middle of November (so it was already icy enough), but it’s entirely possible I just forgot to mention it. The way it works, apparently, is that cool air exerts less pressure than warm air. The air in the bottle is room temperature until hot water is added, which heats the air. But when the air cools, the pressure decreases, and if there’s nowhere for the hot air to go, the pressure of the air outside the bottle is greater than the pressure of the air inside, and the bottle caves in. For some reason… No, I still don’t understand it… Can you explain it to me? Please write to waen@waenshepherd.com and tell me how it works. I’ll write up the best answers here so everyone can see them. So definitely don’t write me silly answers.
Air Pressure
Air Pressure
Water Pressure Air Pressure Air Air Pressure (revisited)
TERM 1 Sept-Dec 1979
TOPIC 1 Sept-Dec 1979
FAIRBURN The place where I wrote all this rubbish
WAEN SHEPHERD Who was this strange little boy?
GEOGRAPHY 1 Sept 1979 - Feb 1981
HISTORY 1 Sept 1979 - Oct 1981
Darth Vader An autograph from a genuine stand-in
The Forgotten World John and Mick fall foul of some extreme potholing
String Orchestra A visit from the North Yorkshire County Council Orchestra
The Old Stone Age Ancient humans try to co-exist with cave lions and giant deer
Christmas 1979 Can Waen last the night without opening his presents?
Bonfire Night Waen’s first time at the annual village fireworks display
Experiment Two Two weeks after the first one, another experiment. And my first thought is: isn’t this a bit dangerous? Hot water in cans that buckle and cave in? The teacher’s really got to be 100% sure his grasp of Physics is up to par, or we could be looking at a class full of maimed kids. Not that anyone would have really cared about that back then. But I’d have a hard time believing you could do this experiment with a bunch of eight year olds in 2021. Again, I’m not sure I’ve written this up in the most effective manner. Yes, I’ve described what happened, but I don’t think I quite grasped why. I mean, if the top’s on, the steam can’t escape, so surely the pressure of the steam - which wants to escape the bottle - must make it explode outwards, not buckle and implode? Got to find a way of explaining it. Maybe using another experiment on the internet will help. OK, here’s one: https://coolscienceexperimentshq.com/how-to- crush-a-bottle/ - This one uses a plastic bottle and, crucially, needs to be lying in a bed of ice, with cold water poured onto it. I expect we managed to skip this part because we were in Yorkshire in the middle of November (so it was already icy enough), but it’s entirely possible I just forgot to mention it. The way it works, apparently, is that cool air exerts less pressure than warm air. The air in the bottle is room temperature until hot water is added, which heats the air. But when the air cools, the pressure decreases, and if there’s nowhere for the hot air to go, the pressure of the air outside the bottle is greater than the pressure of the air inside, and the bottle caves in. For some reason… No, I still don’t understand it… Can you explain it to me? Please write to waen@waenshepherd.com and tell me how it works. I’ll write up the best answers here so everyone can see them. So definitely don’t write me silly answers.
Air Pressure
TERM 1 Sept-Dec 1979
TOPIC 1 Sept-Dec 1979
FAIRBURN The place where I wrote all this rubbish
WAEN SHEPHERD Who was this strange little boy?
GEOGRAPHY 1 Sept 1979 - Feb 1981
HISTORY 1 Sept 1979 - Oct 1981
Darth Vader An autograph from a genuine stand-in
The Forgotten World John and Mick fall foul of some extreme potholing
String Orchestra A visit from the North Yorkshire County Council Orchestra
Christmas 1979 Can Waen last the night without opening his presents?
Bonfire Night Waen’s first time at the annual village fireworks display
Air Pressure
to be continued…