• GiveMemes@jlai.lu
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    4 months ago

    You might’ve already seen this, but try using the method of dimensional analysis where you work backwards on a single line and you’ll never get one of those problems wrong again.

    The key is just working backwards by units using the equations you have available. I know somebody that only got one of the questions on his MCAT correct bc he used this method lol.

    • Sterile_Technique@lemmy.world
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      4 months ago

      I use dimensional analysis, but it’s over two lines… and not sure what you mean by working backwards, since the order doesn’t really matter so long as every value is in the correct line.

      Since typing it out would be ugly as sin, example image stolen from google:

      …they like to give us things like pt weight in lbs and oz, and ask for final product of tablespoons or some shit cuz they enjoy wasting our time, lol.

      That the type you mean?

      I know there are a few different ways to crunch the numbers, but DA is my favorite so far cuz it’s so consistent.

      *edit, example pic changed, first one put mcg twice in the same line, which is a weird move. /shrug

      • oldfart@lemm.ee
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        4 months ago

        So USAnian drugs are in metric units? I hope in actual work nurses get to use a phone app or something because this asks for mistakes

        • Sterile_Technique@lemmy.world
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          4 months ago

          99% of it is metric. I think the biggest outlier is home care, where you go visit some grandma who’s actively offended by metric, so if you tell her to take 7.5mL of something she’ll just do the deer in the headlights thing, then shove the bottle up her ass.

          Tell her instead that she needs to take 3 Mountain Dew caps full and suddenly she can follow instructions enough to not kill herself.

          • oldfart@lemm.ee
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            4 months ago

            I thought everything is bigger across the ocean but your Mountain Dew caps are tiny over there! ;)

            • Sterile_Technique@lemmy.world
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              4 months ago

              Just googled it and apparently they’re about 5mL each. Apparently I’m not great at eyeballing volume.

              Add it to the pile of conversion failures between metric and imperial.

              • oldfart@lemm.ee
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                4 months ago

                Yeah, 5ml is a teaspoon, but I’m not sure if it’s reasonable to assume teaspoons have similar sizes across countries.

                But after your first month in the job you’ll convert and eyeball it even when half asleep :)

                • zod000
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                  4 months ago

                  I know it should be obvious and maybe I missed the sarcasm, but the teaspoon unit is in no way the same as an actual teaspoon utensil. I also don’t use my own feet to measure length.

                  • Sterile_Technique@lemmy.world
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                    4 months ago

                    I didn’t think that was sarcasm, it’s just such a jacked up system of measurement that he’s not confident it doesn’t change with borders, which is honestly a pretty reasonable point of uncertainty.

        • Treczoks@lemmy.world
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          4 months ago

          Even in the US, science is mostly metric. But most US people are not exactly the scientific kind…

          • alcoholicorn
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            4 months ago

            Modern science is, but there’s plenty of old journals from the 80s and earlier that use degrees Rankine and gallons.

            • prole@lemmy.blahaj.zone
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              4 months ago

              Fucking BTUs and shit.

              PSI is another one that seems to be used over the metric/SI alternative in some science-adjacent applications.

              • assassin_aragorn@lemmy.world
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                4 months ago

                Psi is used a lot in engineering. But honestly, pressure units are a bit of a mess. The metric unit is a Pascal, which is fundamentally defined as a Newton per square meter – unsurprisingly, that is an incredibly small quantity of pressure. It’s roughly 101,500 Pascals for standard atmospheric pressure. You’ll typically see pressure written in either kPa, MPa, or bars (1E5 Pascals) within a metric framework. For perspective, it’s 14.7 psi (lbs per square inch) for an atmosphere.

                And personally, I think all of these are pretty silly when we could be using 1 atm instead, which is literally defined as standard atmospheric pressure. It’s a much easier way to visualize and intuitively grasp pressures.

                BTU is another fun one. It’s the energy needed to raise 1 lb of water by 1 degF. Calorie is the energy to raise 1 g of water by 1 degC. Both are very pragmatic definitions and have a degree of intuition. Then they’re the metric unit, the Joule, which suffers from the same issue as Pascal. It’s the work done by a 1 Newton force pushing an object 1 meter. Once again, pretty small.

        • frezik@midwest.social
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          4 months ago

          It works fine when everything around you is in those numbers. The scale for medications might be set to mg, or injections in mL. The bottles for both are labeled the same way. Everything works together, and you don’t really have to think about it.

          Part of the problem with converting everything to metric is it really needs to be everything. You can try talking about driving distances in km, and your gas tank in L/100km, and your speed in km/hr. However, the interstate highway signs will still be in miles, you buy gas in gallons, and the speed limit signs are in mph. This isn’t a case where you can just choose to use the metric system as an individual, because the whole system works against you.

          • oldfart@lemm.ee
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            4 months ago

            That is understandable, I was surprised that metric is actually used somewhere. Use in pharmacy also explains why in Hollywood stoner comedies they used grams, which always confused me.

            • frezik@midwest.social
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              4 months ago

              It’s used all over the place in the US. It’s usually a weird, thoughtless mixture. Milk is sold in gallons, soda is sold in liters.

              In fact, you’ll find exceptions in most countries once you start looking for them. Just a matter of how prevalent the metric system is; nobody is 100%. Most common exception is car tires because of how industry standards work.

        • Sterile_Technique@lemmy.world
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          4 months ago

          Gotcha! Yeah same page - some of the other students don’t like that method cuz it can take a bit longer, but building the equation kinda idiot proofs itself against calculating for the wrong unit, and it’s super consistent! Definitely my favorite so far.

    • GoodEye8@lemm.ee
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      4 months ago

      Even dimensional analysis works best with metric because sometimes you need to convert units and almost all conversion in metric are base 10, so something like 1kg/km is 1000g/1000m is 1 gram per meter. But in imperial 1 pound/mile is 16 ounces / 5280 feet is who the fuck knows how many ounces per feet.