Random Thoughts

[jgb191]

Any of you smart engineers out there that can show me how:

a ∙ b = ab cos θ

From: https://metric.ma.ic.ac.uk/metric_public/vectors/vector_coordinate_geometry/scalar_product.html

And, that's the best I can do....

Thanks!  From your diagram, if we subtract the two vectors, vector c completes the triangle.

c = b - a

The magnitude of c would be the square root of the difference between the two original vectors dotted with itself.  Then squaring the magnitude of c derives something similar to the cosine law.

c^2 = c ∙ c = (b - a) ∙ (b - a) = a^2 + b^2 - 2a ∙ b

Equating that with the cosine law (and dropping the eliminated terms) gives us:

a^2 + b^2 - 2a ∙ b = a^2 + b^2 + 2ab cos θ

a ∙ b = ab cos θ


Do engineers really utilize all the Calculus, Linear Systems, and Differential Equations learned in school?  I know that learning Calculus has helped me project future trends based on previous pattern.

[Scott5114]

Any of you smart engineers out there that can show me how:

a ∙ b = ab cos θ

It helps to know that cos is British English; it is a contraction of because. (In American English, we usually spell this cuz.) Additionally, whoever typed the original sentence was probably in a hurry, because (or cos) they left out the punctuation.

So in American English, this would be:

a ∙ b = ab, cuz θ.

Hope this helps!

[algorerhythms]

Any of you smart engineers out there that can show me how:

a ∙ b = ab cos θ

It helps to know that cos is British English; it is a contraction of because. (In American English, we usually spell this cuz.) Additionally, whoever typed the original sentence was probably in a hurry, because (or cos) they left out the punctuation.

So in American English, this would be:

a ∙ b = ab, cuz θ.

Hope this helps!

No, no, no. In British, 'cos' is a type of lettuce that is called 'romaine' in American. That expression is a recipe for a salad.

[Scott5114]

That expression is a recipe for a salad.

Why's it got a picture of a hamburger at the end then?

[kphoger]

That expression is a recipe for a salad.

Why's it got a picture of a hamburger at the end then?

It's a hard-boiled egg.  Chef's salad.  Chef's sine salad.  Chef's cosine salad.

[Max Rockatansky]

I drove a manual transmission car (a Mexican market Chevy Optra) for the first time in about a decade.  I definitely out of practice given I ran afoul of the stall RPM a couple times in 1st gear.

[Max Rockatansky]

All my wife's family in Mexico keeps trying to give me advice on what roads I should drive.  I've never once gotten any of them lost in all the years I've been coming down here.  I gave the keys to my father in law today and he ended up driving twenty kilometers in the wrong direction after taking an exit early on Federal Highway 54D. 

[Max Rockatansky]

Subway tastes infinitely better in Mexico than it does in the U.S.  They are using different ingredients which is really apparent in the taste of the bread.  I really dig having fries with my sandwich.

[LilianaUwU]

Subway tastes infinitely better in Mexico than it does in the U.S.  They are using different ingredients which is really apparent in the taste of the bread.  I really dig having fries with my sandwich.

Regional differences are probably why I don't get the Subway hate. It's fine in Canada, even if it's nothing remarkable. Then again, I have extremely low standards when it comes to fast food, so there's also that.

[ZLoth]

There is a Jersey Mikes that is extremely close by, followed by McAlister's Deli, Firehouse Subs, Jason's Deli, and then Potbelly Sandwich Shop. Oh yeah, a Charleys Cheesesteaks and Wings.

Subway is a bit further away than those shops. And, it's been months since I had a sandwich.

[JayhawkCO]

I don't think I've gone to a fast food sub place in about four years. Sandwiches with cheese, veggies, and lunch meat are just too easy to make at home for a fraction of the price. When I go out to eat, I prefer to pay for things that are much more easily done in a restaurant setting than in my kitchen.

[Max Rockatansky]

Subway tastes infinitely better in Mexico than it does in the U.S.  They are using different ingredients which is really apparent in the taste of the bread.  I really dig having fries with my sandwich.

Regional differences are probably why I don't get the Subway hate. It's fine in Canada, even if it's nothing remarkable. Then again, I have extremely low standards when it comes to fast food, so there's also that.

Subway was fine until decent prices were locked behind apps.  It is hard to justify a $14 dollar sub when I can go to a real restaurant or deli.  Trouble is the Mexican equivalent is about $7 USD and tastes better on top of the lower price.  But then again, most American food tastes bland or off compared what you get out of the country. 

[kphoger]

All my wife's family in Mexico keeps trying to give me advice on what roads I should drive.  I've never once gotten any of them lost in all the years I've been coming down here.  I gave the keys to my father in law today and he ended up driving twenty kilometers in the wrong direction after taking an exit early on Federal Highway 54D. 

Never, ever, ask someone in Mexico if a certain road goes to a certain place.  The answer will always be yes, even if the road doesn't go there.

[mgk920]

Subway tastes infinitely better in Mexico than it does in the U.S.  They are using different ingredients which is really apparent in the taste of the bread.  I really dig having fries with my sandwich.

Regional differences are probably why I don't get the Subway hate. It's fine in Canada, even if it's nothing remarkable. Then again, I have extremely low standards when it comes to fast food, so there's also that.

I still miss the Subway that was on College Ave (the city's main street) in the heart of downtown Appleton, WI.  From what I am aware of, they closed because their building's systems went to carp.

Mike

[JayhawkCO]

Subway tastes infinitely better in Mexico than it does in the U.S.  They are using different ingredients which is really apparent in the taste of the bread.  I really dig having fries with my sandwich.

Regional differences are probably why I don't get the Subway hate. It's fine in Canada, even if it's nothing remarkable. Then again, I have extremely low standards when it comes to fast food, so there's also that.

I still miss the Subway that was on College Ave (the city's main street) in the heart of downtown Appleton, WI.  From what I am aware of, they closed because their building's systems went to carp.

Mike

Sounds fishy.

[vdeane]

But then again, most American food tastes bland or off compared what you get out of the country. 

Out of Spec Motoring just released a Shanghai to Beijing roadtrip video on their YouTube channel.  One of the things they mentioned at one point is that the burgers in China are better than what they can get in Colorado.

[kphoger]

I drove a manual transmission car (a Mexican market Chevy Optra) for the first time in about a decade.  I definitely out of practice given I ran afoul of the stall RPM a couple times in 1st gear.

No shame in that.  Every car is different, and it's easier to stall some than others.

For example, our current vehicle is a 2002 Ford Focus, and I've never stalled it once—from the first test drive a year ago until now (well, except for once in my own driveway when, after parking, I forgot that I hadn't yet turned it off before taking my feet off the pedals).

In contrast, when we rented a late-model Nissan pickup in Mexico for a mission trip a couple of years ago, I stalled that thing at stop signs probably a half-dozen times within those few days.  It wasn't hard to drive at all, but it was apparently just a little more stall-happy than what I'm driving at home these days.

[Max Rockatansky]

I drove a manual transmission car (a Mexican market Chevy Optra) for the first time in about a decade.  I definitely out of practice given I ran afoul of the stall RPM a couple times in 1st gear.

No shame in that.  Every car is different, and it's easier to stall some than others.

For example, our current vehicle is a 2002 Ford Focus, and I've never stalled it once—from the first test drive a year ago until now (well, except for once in my own driveway when, after parking, I forgot that I hadn't yet turned it off before taking my feet off the pedals).

In contrast, when we rented a late-model Nissan pickup in Mexico for a mission trip a couple of years ago, I stalled that thing at stop signs probably a half-dozen times within those few days.  It wasn't hard to drive at all, but it was apparently just a little more stall-happy than what I'm driving at home these days.

It probably has something to do with the nature of the car having been completely rebuilt.  The engine would drop to 500 RPM and start to stall unless you keep your right foot on the gas.  I was revving up to 1,500 RPM out of a stop into 1st for some measure of reliability. 

The really fun is the 2000 Suburban (from the U.S. market) that I was driving most of the trip.  The starter is all screwed up and tended to keep running when the engine was cold unless you turned the ignition on/off several times.  My father in law and I were going to pull the starter to but we never got around to it given a window motor died the first day of the trip.  We ended up sending the window motor up to Guadalajara and had to reinstall it later on.  Something is wrong with the engine in general (a 5.3L V8 Vortec) as it felt really down on power the entire time.  Apparently this vehicle is kept because it was 4WD. 

Our most reliable vehicle is the 1997 2WD F150.  The only thing weird with this one is the transmission linkage from the column shifter was shortened at some point.  That means 1st gear is unreachable from the shifter and you have to park in the reverse tab. 

We did look at a 2018 Toyota Corolla that one of the cabbies was selling for $2,800 USD.  Pretty fair chance that I'll be going in 50/50 with my father in law to make the purchase and have something small for in-town.

[Max Rockatansky]

All my wife's family in Mexico keeps trying to give me advice on what roads I should drive.  I've never once gotten any of them lost in all the years I've been coming down here.  I gave the keys to my father in law today and he ended up driving twenty kilometers in the wrong direction after taking an exit early on Federal Highway 54D. 

Never, ever, ask someone in Mexico if a certain road goes to a certain place.  The answer will always be yes, even if the road doesn't go there.

I figured the point was conveyed by the time we ultimately got to our destination.  My father in law handed me the keys when nobody was looking and didn't try to tell me where to go the rest of the trip. 

[kkt]

I drove a manual transmission car (a Mexican market Chevy Optra) for the first time in about a decade.  I definitely out of practice given I ran afoul of the stall RPM a couple times in 1st gear.

No shame in that.  Every car is different, and it's easier to stall some than others.

For example, our current vehicle is a 2002 Ford Focus, and I've never stalled it once—from the first test drive a year ago until now (well, except for once in my own driveway when, after parking, I forgot that I hadn't yet turned it off before taking my feet off the pedals).

In contrast, when we rented a late-model Nissan pickup in Mexico for a mission trip a couple of years ago, I stalled that thing at stop signs probably a half-dozen times within those few days.  It wasn't hard to drive at all, but it was apparently just a little more stall-happy than what I'm driving at home these days.

It probably has something to do with the nature of the car having been completely rebuilt.  The engine would drop to 500 RPM and start to stall unless you keep your right foot on the gas.  I was revving up to 1,500 RPM out of a stop into 1st for some measure of reliability. 

The really fun is the 2000 Suburban (from the U.S. market) that I was driving most of the trip.  The starter is all screwed up and tended to keep running when the engine was cold unless you turned the ignition on/off several times.  My father in law and I were going to pull the starter to but we never got around to it given a window motor died the first day of the trip.  We ended up sending the window motor up to Guadalajara and had to reinstall it later on.  Something is wrong with the engine in general (a 5.3L V8 Vortec) as it felt really down on power the entire time.  Apparently this vehicle is kept because it was 4WD. 

Our most reliable vehicle is the 1997 2WD F150.  The only thing weird with this one is the transmission linkage from the column shifter was shortened at some point.  That means 1st gear is unreachable from the shifter and you have to park in the reverse tab. 

We did look at a 2018 Toyota Corolla that one of the cabbies was selling for $2,800 USD.  Pretty fair chance that I'll be going in 50/50 with my father in law to make the purchase and have something small for in-town.

Regarding the Suburban - just what you need, an unreliable 4wd vehicle.  So when it craps out on you it'll be way up some marginal road where AAA isn't gonna go help you out...

[Max Rockatansky]

I drove a manual transmission car (a Mexican market Chevy Optra) for the first time in about a decade.  I definitely out of practice given I ran afoul of the stall RPM a couple times in 1st gear.

No shame in that.  Every car is different, and it's easier to stall some than others.

For example, our current vehicle is a 2002 Ford Focus, and I've never stalled it once—from the first test drive a year ago until now (well, except for once in my own driveway when, after parking, I forgot that I hadn't yet turned it off before taking my feet off the pedals).

In contrast, when we rented a late-model Nissan pickup in Mexico for a mission trip a couple of years ago, I stalled that thing at stop signs probably a half-dozen times within those few days.  It wasn't hard to drive at all, but it was apparently just a little more stall-happy than what I'm driving at home these days.

It probably has something to do with the nature of the car having been completely rebuilt.  The engine would drop to 500 RPM and start to stall unless you keep your right foot on the gas.  I was revving up to 1,500 RPM out of a stop into 1st for some measure of reliability. 

The really fun is the 2000 Suburban (from the U.S. market) that I was driving most of the trip.  The starter is all screwed up and tended to keep running when the engine was cold unless you turned the ignition on/off several times.  My father in law and I were going to pull the starter to but we never got around to it given a window motor died the first day of the trip.  We ended up sending the window motor up to Guadalajara and had to reinstall it later on.  Something is wrong with the engine in general (a 5.3L V8 Vortec) as it felt really down on power the entire time.  Apparently this vehicle is kept because it was 4WD. 

Our most reliable vehicle is the 1997 2WD F150.  The only thing weird with this one is the transmission linkage from the column shifter was shortened at some point.  That means 1st gear is unreachable from the shifter and you have to park in the reverse tab. 

We did look at a 2018 Toyota Corolla that one of the cabbies was selling for $2,800 USD.  Pretty fair chance that I'll be going in 50/50 with my father in law to make the purchase and have something small for in-town.

Regarding the Suburban - just what you need, an unreliable 4wd vehicle.  So when it craps out on you it'll be way up some marginal road where AAA isn't gonna go help you out...

Last year was fun when I had that Suburban out on the Autopistas east of Guadalajara.  I could get up to 70 MPH on flat stretches but it required flooring it.

Usually we take the F150 to the ranch in dry weather.  Said road to the ranch starts as cobblestone but becomes ungraded dirt a couple miles in.   That is a lengthy walk back to town that I don't want to try. 

[Molandfreak]

I miss the Midwest-exclusive Italian Herbs & Cheese bread from Subway. Monterrey Cheddar just doesn't cut it compared to that classic mozzarella and oregano flavor.

[kphoger]

For example, our current vehicle is a 2002 Ford Focus, and I've never stalled it once—from the first test drive a year ago until now (well, except for once in my own driveway when, after parking, I forgot that I hadn't yet turned it off before taking my feet off the pedals).

I decided to test something out today.  When I left for work, before the revs had completely settled down upon warm-up (still at ~1200 rpm), I was able to pull away from the parking space without using the gas pedal at all—just slowly let out the clutch pedal.

Shortly before getting home, I pulled over and tried with a fully warmed-up engine (at ~800 rpm).  Nope, stalled.

[formulanone]

For example, our current vehicle is a 2002 Ford Focus, and I've never stalled it once—from the first test drive a year ago until now (well, except for once in my own driveway when, after parking, I forgot that I hadn't yet turned it off before taking my feet off the pedals).

I decided to test something out today.  When I left for work, before the revs had completely settled down upon warm-up (still at ~1200 rpm), I was able to pull away from the parking space without using the gas pedal at all—just slowly let out the clutch pedal.

Shortly before getting home, I pulled over and tried with a fully warmed-up engine (at ~800 rpm).  Nope, stalled.

I could do this on my previous manual cars; almost seamlessly if you very slowly lifted your foot off the clutch; perhaps taking 5-6 seconds from fully-depressed pedal to fully-released and the engine wouldn't miss a beat. I only tried that in parking lots or around my neighborhood...the bite point for the clutch is notoriously finicky, with a tiny margin of error between idling and stalling from a rest, and that 1st-2nd shift was usually clumsy. So I don't think I tried it more than once or twice in traffic.

Sadly, the transmission started making horrible bearing noises last year and the replace prices made it trade-in fodder after nobody wanted to rebuild it and I didn't want to spend a lot on an as-is junkyard (not rebuilt) transmission.

[PColumbus73]

I've been hearing the phrase "Have a good rest of your day (night)" and it irks me whenever I hear it.

Maybe it's the flow and the way it rolls, but it just sounds clunky versus "Enjoy the rest of your day" or even more simply "Have a good day (night)".