• usernamesAreTricky@lemmy.ml
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      1 year ago

      That’s because of friction and air resistance which are still forces. Repeat the same experiment in outer space where there’s no atmosphere or stuff in the way and you won’t see that

      There’s even things like ion engines that take advantage of that by producing tiny amounts of thrust but run over long amounts of time to build up quite a bit of speed

      https://en.m.wikipedia.org/wiki/Ion_thruster

      • redballooon@lemm.ee
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        1 year ago

        Having taken not only Highschool physics but also university physics courses I know that.

        That doesn’t change that for most people in most environments the sentence “if an object isn’t pushed it’ll stop” is, in fact, true.

        It becomes false only if you change the context, but I would argue, if you know all the facts and scenarios, that’s willful misunderstanding.

      • redballooon@lemm.ee
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        1 year ago

        A statement so general that it is useless.high school physics does so many simplifications that it’s only about very specific experiments in real life, but is generally not very accurate.

        • reliv3@lemmy.ml
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          1 year ago

          As a high school physics teacher, if this is the hill you’re willing to die on, then you neither understood the content in your high school physics class nor your university physics class. Newton’s 2nd law is generally accurate in most scenarios even without simplifications.

            • reliv3@lemmy.ml
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              1 year ago

              Yes, like you stopping to peddle your bike…

              A simple force diagram and application of newton’s 2nd law predicts the bike should accelerate to the left while it’s velocity is towards the right. This means the bike should slow down.