• mvirts@lemmy.worldEnglish
      0·
      2 months ago

      E=mc^2 so m is joule seconds^2 / meter ^ 2

      F=ma so m is Newton seconds^2 / meter

      A joule is 1 Newton / meter so they agree

        • absGeekNZ@lemmy.nzEnglish
          0·
          2 months ago

          A J = Ns not N/s

          One Joule of energy is one Newton of force applied for 1 second.

          • zkfcfbzr@lemmy.worldEnglish
            0·
            2 months ago

            Muphry’s law at work - for both of us, actually. I looked it up (since with Ns the units no longer worked out between E = mc² and F = ma), and a joule is actually a Nm, a Newton-meter. And with that the units do work out correctly on both equations.

            • absGeekNZ@lemmy.nzEnglish
              0·
              2 months ago

              That is really unintuative, torque is Nm…how can energy also be Nm.

              But then I look at it and J = Ws = N(m/s)s = Nm