3 Perplexing Physics Problems

114 884 Áhorf 2,4 m.

Why does shaken soda explode? Does ice melt first in fresh or salt water?
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This video features experiments that have been shown to me by science teachers over the years. Does ice melt fast in salt water or fresh water was an experiment introduced to me at the Utah Science Teachers' conference. The ring of metal over a chain demo came from a teachers event in Florida. The idea shaking a carbonated drink increases pressure came from an email.
Special thanks to Petr Lebedev for building the pressure gauge.
Links to literature are below:
Victims of the pop bottle, by Ted Willhoft. New Scientist, 21 August 1986 p.28
Carbonation speculation
The Physics Teacher 30, 173 (1992); doi.org/10.1119/1.2343501
Agitation solution
The Physics Teacher 30, 325 (1992); doi.org/10.1119/1.2343556
Filmed by Cristian Carretero, Jordan Schnabel, Jonny Hyman, and Raquel Nuno
Music from epidemicsound.com "Seaweed" "Quietly Tense" "Mind Shift" "Observations"


  1. Java Viper312
    Java Viper312
    50 mínútum síðan

    When I press on a shaked soda and a non shaked soda the shaked soda seams to be harder to press on. So how does that not be a difference in pressure

  2. 4285kenni
    Klukkustund síðan

    But mentos trick does not work on normal coladrinks, only those that are sugar free. Mythbusters tested this.

  3. Julio figo
    Julio figo
    2 klukkustundum síðan

    Cool and fun! tks!

  4. Alex Gideon
    Alex Gideon
    3 klukkustundum síðan

    After 90 days of no fap 10:57

  5. michael
    4 klukkustundum síðan

    I feel like though I've felt a bottle of soda get harder after I've shaken it though

  6. Toro Roro
    Toro Roro
    5 klukkustundum síðan

    favorite physics teacher

  7. Marius du Plessis
    Marius du Plessis
    5 klukkustundum síðan

    damned interesting about the soda. I knew about tapping the bottle on the side when it fell for example and you wanted to open it, but not about the pressure. Dropped a bottle of soda yesterday and thought it might pop as it was a 450ml one.

  8. Marius du Plessis
    Marius du Plessis
    6 klukkustundum síðan

    @6:53 "Me from the future"

  9. Call Me Perseverer1
    Call Me Perseverer1
    6 klukkustundum síðan

    I think it's may not be a problem it's the solution. Keep it up! :)

  10. Zed orda
    Zed orda
    7 klukkustundum síðan

    5:26 But how did you get the fly to go through the ring is the real question?

  11. Robert Lewis
    Robert Lewis
    9 klukkustundum síðan

    Heh, I had tehe right idea about the first solution. (The third was pretty much explained the moment I saw the slow-mo, though....)

  12. Toby Wenman
    Toby Wenman
    12 klukkustundum síðan

    But when you shake a bottle of coke the bottle definitely gets harder/expands a little bit. I don't understand how the pressure couldn't go up.

  13. Cheese
    14 klukkustundum síðan

    Absolutely loved this. Thanks so much

  14. Virgilio Greco Baptistella
    Virgilio Greco Baptistella
    17 klukkustundum síðan

    All my life I have hated straws for apparently making soft drinks taste more bubbly than normal! Now it is confirmed, just compare, drinking from a cup and with a straw. When you drink directly from a cup's edge, the liquid only touches the edge of the cup, while using the straw the liquid flows through the entire body of the straw (more surface), creating that unpleasant gas (at least for me).

  15. The Love Of Awesomesauce
    The Love Of Awesomesauce
    17 klukkustundum síðan

    I thought it said psychic so I was getting my third eyed ready.

  16. Tasos Daris
    Tasos Daris
    19 klukkustundum síðan

    I'm not sure that we throw salt in the streets in order to melt the ice. I always thought that we threw it in order to prevent the melted snow (water) to freeze.

  17. gotwoh3ll
    21 klukkustund síðan

    So why when i shake the bottle do i feel it get tighter

  18. mwaura erick
    mwaura erick
    Degi Síðan síðan

    Soda is harmful to your health

  19. Joseph Johnson
    Joseph Johnson
    Degi Síðan síðan

    Wouldn’t part of the ice cube explanation be freezing point depression? The salt depresses the freezing point of water which in turn means the salt water mixture can get colder, and that would lead to less heat transfer to the ice cube. Which means it would melt slower.

  20. Dave Morgan
    Dave Morgan
    Degi Síðan síðan

    Outstanding video! Loved it! Made me wonder though, can you tell me what the water is doing inside of a pressure cooker? I suspect after a time it is NOT boiling even though the water will be above its boiling point. Is there any way to confirm?

  21. Roman KFM
    Roman KFM
    Degi Síðan síðan

    I love this channel so much.

  22. deflex
    Degi Síðan síðan

    Are the slomo sounds real?!

  23. ccgsales
    Degi Síðan síðan

    Nucleation huh? So tapping a soda can lid before you open it really DOES help prevent overflow!

  24. Mikkel Ulstrup
    Mikkel Ulstrup
    Degi Síðan síðan

    Great video! Though you left me with one question: Why does the pressure increase in the soda bottle until 3 atmospheres but no further?

  25. Te[NO
    Degi Síðan síðan

    To the Coke bottle Experiment, why is IT Not possible to compress the bottle after shaking If the presure ist the Same ?

  26. Cassandra Thompson
    Cassandra Thompson
    Degi Síðan síðan

    I'm no physicist, but I don't think that "no ammount of shaking..." is true. Wouldn't shaking it enough to increase the temperature also increase the preasure since we're adding heat to the system from all that kinetic flappin about?

  27. John Riley
    John Riley
    Degi Síðan síðan

    Between 4:16 and 4:29 (at 0.25x speed, of course), look to the left half of the chain to understand the phenomenon. This is because the beads on the right side bunch up to make it look like two interlocking parts of the chain to offer a distorted perspective. You'll waste a lot of time if you look to that side. Just FYI.

  28. Sylvain
    Degi Síðan síðan

    Funny how much "simple" experiments can teach you a lot ! Thank you :)

    Degi Síðan síðan

    All the people just watched the video and voted

  30. Follow Media
    Follow Media
    Degi Síðan síðan

    8:47 it's technically misleading to say it's under 1atm of gauge pressure upon uncapping, but rather only 4E-4 atm. because in this case only the partial pressure of CO2 in the atmosphere is relevant. opening a soda bottle into our atmosphere is as good as opening the bottle into outer space where the drink going flat from CO2 loss is concerned. you can confirm this by opening the bottle, recapping it, pumping atmopheric air into the headspace back to 3atm, then shaking the bottle. gauge will rise to 6atm despite the dissolved CO2 being only 3atm.

  31. Follow Media
    Follow Media
    Degi Síðan síðan

    6:30 should have just Schlieren imaged the melting ice in both cases to compare :)

  32. Wilson
    Degi Síðan síðan


  33. Rose White
    Rose White
    Degi Síðan síðan

    bottle geysers for the same reason boiler explosions are so deadly. As soon as a small openiong in bottle or crack in boiler occurs the adjacent compressed liquid can immediately flash into vapour and then the next and the next until a chain reaction of flashing occurs right through the liquid until all the pressure has dropped to atmospheric. With hot water in boilers obviously more of the liquid will flash off. This is the reason why shaking a can of pop then trying to cut it open will cause a mini explosion that rips the can open.

  34. Rene Schickbauer
    Rene Schickbauer
    Degi Síðan síðan

    Veritasium: I read sometimes things like "this moon was probably a small planet captured my this giant planet". I may missunderstand the slingshot effect, but wouldn't this result in retrograde orbit? If the flyby was prograde, wouldn't this accelerate the object out of orbit?

  35. neomt2
    2 dögum síðan

    He got a rich house

  36. Thomas Klitgaard
    Thomas Klitgaard
    2 dögum síðan

    Hey Veritasium :) What happens when you freeze a coke and let it heat up again. why does the coke expand when it freezes and why is there gas still inside it?

  37. Schwurbel
    2 dögum síðan

    Is it really just the rough surface of a Mentos? A kind of porous but ohter wise non-reactive ceramic would work as well?

  38. Samantha de Regules
    Samantha de Regules
    2 dögum síðan

    The sound of the ring sliding down the necklace in slow-mo is orgasmic

  39. Cereal Killer
    Cereal Killer
    2 dögum síðan

    Nice house 🙂

  40. Mr.Everyman
    2 dögum síðan

    Paper straws? Sorry, the rest of the country is not completely insane like the folks in Cali.