Mine brain just does 0.75 × 4.
Thought process was…
- Get 1% = 0.75
- Double it = 1.5
- Double it = 3
Comment on Fucking math...
idegenszavak@sh.itjust.works 18 hours ago
My engineering brain says it’s 3.25.
4% is ~ 5%. 10% of 75 if 7.5. To get the 5% I have to divide it by 2, so 4% of 75 is close to 3.25. I will have to multiply it with some safety coefficient at the end, so the exact value doesn’t matter.
saltesc@lemmy.world 11 hours ago
One_Honest_Dude@lemmy.world 18 hours ago
I’m confused by this statement, the answer is 3. Why do all these extra steps for a wrong answer?
idegenszavak@sh.itjust.works 17 hours ago
It’s not wrong, it’s close enough. And the point it works with more numbers and more type of calculation. Let’s calculate 4% of 1243. That’s the same as 1243% of 4, right, much easier to calculate by simply changing the 2 numbers… While my method is the same, by simply rounding everything.
And in engineering you always multiply/divide your results by a 1.5 or 1.25 safety factor, depending on situation. So you don’t have to calculate exact results, just close enough. E.g. G is always 10m/s2. π is only 3.14, the other digits doesn’t matter.
shrugs@lemmy.world 8 hours ago
That’s the stupidest shit I have heard today. You should feel ashamed if you really are an engineer
Vegiforous@piefed.ca 6 hours ago
That's how engineering is. In civil you can round π=5 for a lot of calculations. In astrophysics I've seen e=π=10
zakobjoa@lemmy.world 18 hours ago
That’s exactly why we have safety coefficients.
IhaveCrabs111@lemmy.world 16 hours ago
Safety coefficients are for nerds
SatansMaggotyCumFart@piefed.world 18 hours ago
That’s why you can always double the maximum limits engineers give.
60 mph roadway?
I can do 120 on it no problem.
Eight person elevator? Sixteen.
0.08 BAC? 0.16 easy peasy.
idegenszavak@sh.itjust.works 17 hours ago
Yes, in elevators usually one cable could hold far more than the full weight, than they add 6 more for the safety.
For rail speed limits this is the exact way they calculate it. For road speed limits they consider break distance, which grows by the square of your speed, so if you go 120 on 60 road, you will need 4 times the distance to stop. I wrote 1.5 as a safety factor, not 4, With a 1.5 safety factor you can go by 75 though, but I would use a 1.1 safety there, as in my country the speed cameras are set up that way, you can go +10% of the official speed limit, they only send a cheque if you went even quicker than that.
atomicbocks@sh.itjust.works 15 hours ago
That’s because elevators use counter weights usually equal to the weight of the car and half the occupancy load so that it takes less energy to lift it and if it falls for any reason it won’t hit the bottom as long as the counter weights are still attached. The occupancy load is determined by the counter weighting system not the cable load capacity.
Buddahriffic@lemmy.world 11 hours ago
Yeah, as I understand it, the elevator will refuse to move instead of collapse, and hopefully you’re not between floors when it happens because it was close and someone shifted their weight or bounced slightly or they might write a sitcom episode about what happens next (and the reality will be far more boring).
Venator@lemmy.nz 7 hours ago
They send you a cheque for speeding? Sounds like you should be going at least 1.11x to collect your bonuses 😜
DancingBear@midwest.social 9 hours ago
Can I also smoke two joints before I smoke two joints, and then smoke two more?
Slatlun@lemmy.ml 9 hours ago
At that point you will have smoked 4% of 100 joints. Hey, math is easy.
DancingBear@midwest.social 8 hours ago
How do Europeans even measure weed lol
jballs@sh.itjust.works 11 hours ago
Did engineers come up with that last one though?