I left school 45 years ago none the wiser about sin, cosin and tangents. I was totally baffled by the concept. Today at 61 years old I learnt what they are and just how cool physics is. That’s the difference a decent teacher makes. Thank you Diana.
I could cry when looking at my like dislike ratio. I have so many jealous people that my videos always get way more dislikes than likes. Please don't be jealous, dear pk
@@hafsaalneyadi8355 North East means a direction bisecting 90 degrees of N and E, so the theta will become 45 degrees thus, 4 multiplied by sin(45) will give you the answer.
I vaguely remember struggling through trig in 10th grade and hated it, though I went on to become an EE. I'm now retired and don't think I ever used that "wonderful" math stuff since college. I have no idea why I even clicked "Trig Review," but am glad I did. I understood more from your video than an entire course. Thanks!
9:11 This is pretty useful, I never realized the sine and cosine for those angles are such neat values. They're even easier to memorize, if you think of them as: √0/2 (= 0/2 = 0) √1/2 (= 1/2) √2/2 √3/2 √4/2 (= 2/2 = 1)
Vector analysis is used extensively in aviation. E.G. to calculate a "crab" angle to use in compensating for a crosswind in order for the plane to travel a straight line to the destination.
We were taught this acronym to remember trig ratios: Some(sin) People(perpendicular) Have(hypotenuse), Curly (cos) Brown (base) Hair (hypotenuse) Tightly (tan) Pulled(perpendicular) Back (base).
I have been downloading all of your Physics 101 videos into a folder I keep on my computer so that I can become more acquainted with Physics. Some times I watch your videos and my brain starts to hurt, so this way if I need to watch them more then once i can just go to my folder and watch them as many times as i need until the info sticks, then I can also quiz myself by watching your video and then when you ask a question, I can pause the video and see if I have learned enough to be able to answer your question. it is slow going, but I am learning about physics because of your videos. so THANKS TEACH!.
Diana, you are a one woman army battling the spirit of the times! Please keep it up! This was the best video, especially in terms of concept, that I've seen in a while!
You know, Dianna, this Physics 101 series has turned out to be far more interesting than this 60-year-old IT guy ever would have thought. My grasp of math stumbled when we hit trig in high school. Bad student/teacher combo never had me recovering. All these decades later, my mathematical illiteracy is annoying. The content you, Jade (Up and Atom) and Matt (PBS Spacetime) present would see me benefit from revisiting those tarnished skills. Remedial math incoming. Thanks for the inspiration.
1:41 In either orientation of the triangle the sides, as the angles get towards 90 90 0, could be 1 1 0, or any finite length no need for them to be infinite. It would be a line segment instead of a line
Thanks so much for this refresher, it has been MANY years since my trig class. Note that at 4:22 you said "ratio of the adjacent side to the hypotenuse" but I think you meant "ratio of the OPPOSITE side to the hypotenuse". I was confused because the math didn't work out, until I realized it's the ratio of the opposite side to the hypotenuse. I'm sure it takes a million takes to present so much information. I love the clear presentation with the sharpie drawing as you go. Would love more videos like this!
I'm a builder, and often work in tree removal, and dynamic loads, I like your easy to understand explanation of advanced confusing math that we use in our business to calculate things, I have always understood the basics of it, but never been great at using it, only minimally understand sochatoa...
I have no idea where the solutions are so for anyone wanting to compare the results of the exercises: Problem 1: Both north and east velocity are equal at 2.83m/s Problem 2: Force upwards 600N, force sideways 1,039.23N Problem 3: Angle is 60° and the velocity is 3.46 m/s I'm not sure about the last one though.
It has been more than 25 years since I was enrolled in trigonometry at University. I'm quite disappointed to see how many of these Concepts I have banished from memory. Time to refresh. I forgot how interesting this really is! Love it!
Trig knocked me out of pre-med at OSU…3 times…I had to drop the 3 hr class & then I finally changed my major! Oh well…I would have been a lousy Doctor anyway as I barely tolerate people anymore, LOL! Diana, you are great, glad I recently found your channel, thanks.☮️
Nice! I majored in chemistry, but I took as many physics classes as possible in college (1970's!!!). I plan to go through your entire series. Thank you!!
If my teachers were half as good at explaining and demonstrating as Diana. I might've actually pursued a higher education. I'm 34 and just now understood sin, cos and tan. Truly enjoyed this video, thank you Diana :)
Giant Atom Inc. yeah, we do! Had a few really good teachers but I had a physics teacher in HS who hated me - I asked questions he didn’t like - got back at him by becoming a physicist! Totally obsolete now, but it was fun while it lasted. 😂
10:50 i don't understand how you can end up with about 10n downward and 17n forward with the real total force being 20n. it feels like you are getting more force out than you are putting into the system.. I guess it has something to do with each direction sharing the force across different directions? i.e. a percentage of the downward force is simultaneously contributing to the forward force and vice versa? I guess I'm just having trouble visualizing the relationship on a physical level between the two vectors and the total force in the system.
This is a tricky one and I am not sure how to actually explain it. I think it is easiest to visualise on unit circle. Or with squares.The area of the squares of the adjacent and the opposing sides combined is the area of the square of the hypotenuse. That is what matters and is constant. And yes when you are adding up vectors, you need to take their direction into account, I always imagine the component forces forming a rectangle and its diagonal is the final force.
I like how you point out that there is a pattern in the sine values of 0 30 45 60 and 90 by adding (√1)/2 and (√4)/2 in the list! I have never noticed that pattern despite using trigonometric functions on a daily basis!
11:02 When I was learning about it in my class, I had a misconception that the resultant vector will have the magnitude of the sum of its two components.
Trig is useful for physics because vectors, represented as arrows, can be broken up into perpendicular components, which is where trig comes into play. Thanks so much for the video!
Your extra credit question has a real life use for me. I enjoy sailing and two big things we look at is Speed Over Ground (SOG) and Velocity Made Good (VMG) to our destination and I knew generally how it is figured but it being several years since high school trig class, it was good to see a refresher course on vectors.
Derivatives integrals trig identities I remember it still after 32 years of not using it. One thing trig and calculus taught me in engineering was voltage can never change instantaneously across a capacitor nor current thru an inductor or coiled wire cannot change instaneously. This is absolutely confirmed thru trig and calculus. Not to mention many many other concepts also. Trig is the foundation of electronic engineering. Neat.
Physics Girl I just found you on the" It's Ok to be Smart" channel. I need these intelligent videos more than ever now. Thank you for the antidote to the cut/paste, opinion vomiting nonsense that is unfortunately the UA-cam norm.
Great timing! I'm teaching this very topic in my AP Physics 1 class tomorrow (Fri., 9/11). Just started vector components after having taught graphical vector addition. When explaining what a vector is, I explain that a magnitude is a 'how much' and the direction is the 'which way' the 'how much' acts. Using two 10 letter words to define a 6 letter word doesn't necessarily improve understanding. Another good resource on trig and vectors is the Mechanical Universe episode (#7?) On vectors available here on UA-cam.
I never saw an answer to the problems. It means that most of the viewers are not learning at all. It is so basic, if you learned the concept of Trigonometry when you were 5 years old... Happy watching.
Yes Dianna, you make physics fun. So many cool things you can do and figure out!. Now I know how those laser distance calculators can tell you how tall a building is by pointing at the top.
Thanks for this video. My 7th graders, that are rocking math, always start getting trig functions when they take adaptive tests. Now I can direct them to this a couple weeks before and win any bragging rights they can👍
I just realized who you are reminding me of... my old Algebra I teacher I had in 8th grade. It isn't that she taught a lot of trigonometry, but in how she taught. She would use an overhead projector with a scrolling loop of celophane that she would write on so that she could go back to previous things she had done if need be, etc. The way you are writing on these pieces of poster board remind me of that. Your presentation by voice and humor also remind me of her. I never really learned acronyms like SohCahToa, etc. because I just don't learn that way... I have different methods for remembering the trig rules like this... basically two rules: Tangent is opposite over adjacent, and TAN=SIN/COS. From those two rules, you can derive the rest.
@@JNCressey Imagine starting on the north side pole, going south to the equator, moving 1/4th easth and then back to the north pole. Those are 3 x 90° angles and an equilateral triangle.
@@jaypaans3471, yes. I know. A sphere is a curved surface. And while the space a sphere is embedded in must be at least 3D, there surface of a sphere, itself, is 2D.
Teacher Dianna, where were you in the time past when slide rules ruled. Only could manage a basic handle on to use it. Have learned more from you in a few lessons than 4 years of mathematics. Thanks Teacher Dianna.
One tool you didn't bring to the table was a sine bar. It's a flat bar with round parts at each end, like a little car whose wheels don't turn. It's used by putting a stack of blocks under one of the round parts, while leaving the other round part on the table. This makes a triangle of the height of the stack of blocks, the table, and the line between the bottoms of the two circles. Since the length of that line is the same regardless of how the bar is tipped, the angle of the bar to the table is the sine of the size of the stack divided by the fixed length. This lets you get any exact angle if you've got exact blocks and a table of sines, and if you can remember what the tool is called, you'll remember that sine is opposite over hypotenuse.
Why didn't anyone ever teach me that sin 30 is root 1 over 2 and that sin of 90 is root 4 over 2 instead of 1/2 and 1 respectively? I know they are the same, but now the pattern mak a sense (in a way the Unit Circle never did)!
Well, unit circle is really nice, but I agree that the pattern is much nicer with the roots making sense. btw sin 0 is root 0 over 2 (insert MINDBLOWN meme)
After 40 plus years as a manufacturing machinist and CNC programmer I still struggle with Trig every day. I have no concept of what it is to be so clever that some find this stuff easy. Dianna did not explain this well but most of our modern world runs on Trig. GPS would be useless without this sort of math. I just enjoyed watching someone who is so excited about a subject I dread.
Does anybody knows the answers of those 3 exercise ? I got answers of problem sets as follows: 1. Opposite(NORTH) = 2.83 ( I applied sin45 ), EAST(cos45) = 2.83 2. Problem 2: What component of that force is up ? => DON'T KNOW THE ANSWER How much of it sideways, parallel to the sideways, parallel to the water? Ans. is (opposite/sin60°=) 1039.23N 3. What is the angle of your resulting velocity vector ? => DON'T KNOW THE ANSWER How fast are you swimming over the riverbed ? => DON'T KNOW THE ANSWER Please correct me.
I got the same answers as you for the first two questions but you forgot to add the answer for the horizontal force of the kite which I found to be 600N.
Perfect timing, I am about to have a test on this topic in a few days! We just learned about how to use trigonometry in projectile motion, so this really helps! I must study aaaaaaaa.
Hi Dianna, I have a doubt, can you pls solve it? Why don't we place the aircraft engine above the aircraft's wings? Because the high speed air will flow above the wing and hence due to cavitation be pulled up and therefore create more lift. Can you please tell why don't we place the propellers above the wings?
So even though the musical group One Direction was vector at one point in time, they all split up with different vectors (directions) later on? I wonder if momentum was conserved?
If the hand is holding steady it would have to be applying the same force towards the person and upward, but the leash itself is pulling down on the hand, not upward.
@@emersonpropst2886 Exactly, the leash is pulling down so the *downward* force should be positive. The Fy force can be negative, if the y is pointing up, but then it is a negative _upward_ force really.
@@NetAndyCz I see what you are saying. My assumption was that she set the coordinates with x being positive toward the dog from the person, and y being positive upward starting at the ground (which at least in my high school and college physics classes was the default)
@@emersonpropst2886 Yeah, it is the usual default, the Fy is negative (and the actual direction of the force is downward). It is just weird and imho wrong to say that the _downward_ force is negative...
Wish you had drawn a unit circle to explain what sine and cosine really mean, rather than triangle ratios that happen to arise from them. Some people think it needlessly complicates things but I find it's much easier to grasp when you know what's really happening.
Dianna, if you were an ANT in the top right corner of a rectangular room measuring 10 foot high by 15 feet wide by 20 feet long, what is the shortest distance to the diametrically opposed corner on the ground and you are an ANT and need to crawl there, what is the shortest distance, on the interior surface?
Wondering how, given a real situation and not drawings, how do you get the measurements to fill the formulae. How do you measure a dog's pull while walking, the wind's pull while more surfing, etc. Loving applied physics.
In India we mostly take the value of sin 45 as 1/√2, so when Diana wrote it as √2/2 I got bit confused 😅😅 Anyways great class as it refreshed my memory. Thanks a lot Diana, really appreciate it❤️❤️
Oh, I hated trig, we had a unit in my geometry class, and they tried to make me, a dyslexic person who can barely remember a phone number, memorize the whole conversion table, I failed so badly that I failed the whole year of geometry, where I had been an A-B student for the rest of the year with almost no effort at all.
There are two ways of teaching this, and the way that emphasises triangles never worked with me. I know this stuff quite well, but thinking about it in terms of ratios of the lengths of the sides of a triangle is not intuitive to me. Looking at in terms of a circle makes a lot more sense to me me. All of a sudden I can easily remember which function does what. For example, tan is the slope of the tangent of point on the circle. Cos and sin are the x and y coordinates of the point in cartesian coordinates. Perhaps it's my programmer mind that prefers this description, but I'm pretty sure I'm not the only one given the number of times I've heard people having problems with intuitively understanding this.
Diana, your penmanship with a sharpie is amazing!
I left school 45 years ago none the wiser about sin, cosin and tangents. I was totally baffled by the concept. Today at 61 years old I learnt what they are and just how cool physics is. That’s the difference a decent teacher makes. Thank you Diana.
Dianna trying so hard with the puns and still succeeds....
I could cry when looking at my like dislike ratio. I have so many jealous people that my videos always get way more dislikes than likes. Please don't be jealous, dear pk
yeah, she's really hammering those home.
💝💖
@@AxxLAfriku go away
At 11:20 she should have used the last tool pun. "Here are some problems to work at home to really (screw) drive these concepts home."
11:27 Problem 2: Up force - 600√3 N
Sideways force - 600 N
How?
Answers?
.
.
.
1) n and e both 2.83 m/s
2) horizontal: 600 N vertical: 1039.23 N
3) theta: 26.6deg, x=1.12m/s
how do you solve Q1?
@@hafsaalneyadi8355 North East means a direction bisecting 90 degrees of N and E, so the theta will become 45 degrees thus, 4 multiplied by sin(45) will give you the answer.
Hey Mark, are u sure velocity over riverbed is 1.12 m/s ??
I got 2.23 m/s with both sides and angle as 26.56 degrees.
@@bgm_identifier No, I definitely am not sure I'm right. You likely are correct.
@@bgm_identifier I got angle 63.4
I really like these more "tutor" type videos with writing and drawing. More please :-)
These puns will help trig-ger my memory for sure 😏
Makes cents! 🤪
I vaguely remember struggling through trig in 10th grade and hated it, though I went on to become an EE. I'm now retired and don't think I ever used that "wonderful" math stuff since college. I have no idea why I even clicked "Trig Review," but am glad I did. I understood more from your video than an entire course. Thanks!
9:11 This is pretty useful, I never realized the sine and cosine for those angles are such neat values.
They're even easier to memorize, if you think of them as:
√0/2 (= 0/2 = 0)
√1/2 (= 1/2)
√2/2
√3/2
√4/2 (= 2/2 = 1)
Yep. Just add 0.7071 and 0.8660 to your mental library and you'll be drillin' it!
Yeah I’d never made the connection of that pattern before 😊
"Physics made easy by Diana"
Agreed
Noice
wdym? it's the same as in school... equally awesome! instead of a board, it's paper
I second that
Not really
Vector analysis is used extensively in aviation. E.G. to calculate a "crab" angle to use in compensating for a crosswind in order for the plane to travel a straight line to the destination.
We were taught this acronym to remember trig ratios:
Some(sin) People(perpendicular) Have(hypotenuse),
Curly (cos) Brown (base) Hair (hypotenuse)
Tightly (tan) Pulled(perpendicular) Back (base).
Some Old Hen -> sin opposite hypotenuse
Caught Another Hen -> cos adjacent hypotenuse
Taking Oats Away -> tan opposite adjacent
@@shanehebert396 Oo nice...
"HIS BIS(cuits)"
- Height Is Sine,
- Base Is Cosine.
This is when the hypotenuse is 1, and the angle you're using is the one at the base.
11:22 Problem 1: 2√2 m/s North and 2√2 m/s East (assuming North East vector make π/4 with East).
>trig
wassup papa
What a coincidence. I was studying Trigonometry right now!!
Will Update/Edit on the lesson ;)
I have been downloading all of your Physics 101 videos into a folder I keep on my computer so that I can become more acquainted with Physics. Some times I watch your videos and my brain starts to hurt, so this way if I need to watch them more then once i can just go to my folder and watch them as many times as i need until the info sticks, then I can also quiz myself by watching your video and then when you ask a question, I can pause the video and see if I have learned enough to be able to answer your question. it is slow going, but I am learning about physics because of your videos. so THANKS TEACH!.
I am literally obsessed with Diana's style of teaching.....!
Diana, you are a one woman army battling the spirit of the times! Please keep it up! This was the best video, especially in terms of concept, that I've seen in a while!
Loving learning physics at 32. Wish I had a teacher like her during my school days. Lots of respect for you diana teacher.
“I learned very early the difference between knowing the name of something and knowing something.”
― Richard P. Feynman
🔞💛🍑💖
@@april18f.u..e0nyic5 R.P. Feynman is very disappointed by you .
You know, Dianna, this Physics 101 series has turned out to be far more interesting than this 60-year-old IT guy ever would have thought. My grasp of math stumbled when we hit trig in high school. Bad student/teacher combo never had me recovering. All these decades later, my mathematical illiteracy is annoying. The content you, Jade (Up and Atom) and Matt (PBS Spacetime) present would see me benefit from revisiting those tarnished skills. Remedial math incoming. Thanks for the inspiration.
1:41 In either orientation of the triangle the sides, as the angles get towards 90 90 0, could be 1 1 0, or any finite length no need for them to be infinite. It would be a line segment instead of a line
Thanks so much for this refresher, it has been MANY years since my trig class. Note that at 4:22 you said "ratio of the adjacent side to the hypotenuse" but I think you meant "ratio of the OPPOSITE side to the hypotenuse". I was confused because the math didn't work out, until I realized it's the ratio of the opposite side to the hypotenuse. I'm sure it takes a million takes to present so much information. I love the clear presentation with the sharpie drawing as you go. Would love more videos like this!
11:32 Problem 3
63° with a resultant velocity of √5 m/s
Measured from the riverbank, angle is 27 deg.
I'm a builder, and often work in tree removal, and dynamic loads, I like your easy to understand explanation of advanced confusing math that we use in our business to calculate things, I have always understood the basics of it, but never been great at using it, only minimally understand sochatoa...
I have no idea where the solutions are so for anyone wanting to compare the results of the exercises:
Problem 1: Both north and east velocity are equal at 2.83m/s
Problem 2: Force upwards 600N, force sideways 1,039.23N
Problem 3: Angle is 60° and the velocity is 3.46 m/s
I'm not sure about the last one though.
It has been more than 25 years since I was enrolled in trigonometry at University. I'm quite disappointed to see how many of these Concepts I have banished from memory. Time to refresh. I forgot how interesting this really is! Love it!
Trig knocked me out of pre-med at OSU…3 times…I had to drop the 3 hr class & then I finally changed my major! Oh well…I would have been a lousy Doctor anyway as I barely tolerate people anymore, LOL! Diana, you are great, glad I recently found your channel, thanks.☮️
I’m still lost!!! On to the next video!
Nice! I majored in chemistry, but I took as many physics classes as possible in college (1970's!!!). I plan to go through your entire series. Thank you!!
If my teachers were half as good at explaining and demonstrating as Diana. I might've actually pursued a higher education. I'm 34 and just now understood sin, cos and tan. Truly enjoyed this video, thank you Diana :)
Whenever I hear the word "vector," my mind always quotes the movie Airplane! "What's our vector, Victor?" Lol
Yeah, and my name actually IS Victor. In school, my nerdy friends ran that line by me all too often, heh.
That's what you think of? Surely you can't be serious...
@@Woad25 I am serious. And don't call me Shirley! :D
i think of vector perkins
Thank you so much Diana, I am really very obliged to you!! THANKS A MILLION!!
I swear that was a whole semester of math in hs and you did it in 10 minutes! :-)
I wish this video was out in the early 1990's when I took trig.
Ferrari King ‘90’s...try 60’s, youngster! 😂😂. Of course, my teachers never looked like Dianna...
Giant Atom Inc. no they were either my current age (I.e., as in methuselah) or men...so, no Dianna’s...
Giant Atom Inc. yeah, we do! Had a few really good teachers but I had a physics teacher in HS who hated me - I asked questions he didn’t like - got back at him by becoming a physicist! Totally obsolete now, but it was fun while it lasted. 😂
10:50
i don't understand how you can end up with about 10n downward and 17n forward with the real total force being 20n.
it feels like you are getting more force out than you are putting into the system..
I guess it has something to do with each direction sharing the force across different directions? i.e. a percentage of the downward force is simultaneously contributing to the forward force and vice versa?
I guess I'm just having trouble visualizing the relationship on a physical level between the two vectors and the total force in the system.
This is a tricky one and I am not sure how to actually explain it. I think it is easiest to visualise on unit circle. Or with squares.The area of the squares of the adjacent and the opposing sides combined is the area of the square of the hypotenuse. That is what matters and is constant.
And yes when you are adding up vectors, you need to take their direction into account, I always imagine the component forces forming a rectangle and its diagonal is the final force.
I like how you point out that there is a pattern in the sine values of 0 30 45 60 and 90 by adding (√1)/2 and (√4)/2 in the list! I have never noticed that pattern despite using trigonometric functions on a daily basis!
11:02 When I was learning about it in my class, I had a misconception that the resultant vector will have the magnitude of the sum of its two components.
same
Not me jumping with joy at finally being able to understand what trig was trying to tell me so can use for physics. Thank you so much.
Please do not stop this series until it is finished...love from 🇮🇳
Trig is useful for physics because vectors, represented as arrows, can be broken up into perpendicular components, which is where trig comes into play.
Thanks so much for the video!
I’m so glad you happen to be doing this series at the same time that I am taking my first physics course!
Your extra credit question has a real life use for me. I enjoy sailing and two big things we look at is Speed Over Ground (SOG) and Velocity Made Good (VMG) to our destination and I knew generally how it is figured but it being several years since high school trig class, it was good to see a refresher course on vectors.
Hey Diana!! Just, wanted you to know, your channel is the reason I LOVE physics. You're AWESOME!!!!
As an engineer, the mnemonic we were taught in college to remember SOH CAH TOA was very rude. Which is why I remember it 50 years later.
“The mind is not a vessel to be filled, but a fire to be kindled.”
― Plutarch
I always wondered what those buttons did on the calculator. Your one of the best teachers I've ever seen
Derivatives integrals trig identities I remember it still after 32 years of not using it. One thing trig and calculus taught me in engineering was voltage can never change instantaneously across a capacitor nor current thru an inductor or coiled wire cannot change instaneously. This is absolutely confirmed thru trig and calculus. Not to mention many many other concepts also.
Trig is the foundation of electronic engineering. Neat.
Physics Girl I just found you on the" It's Ok to be Smart" channel. I need these intelligent videos more than ever now. Thank you for the antidote to the cut/paste, opinion vomiting nonsense that is unfortunately the UA-cam norm.
Great timing! I'm teaching this very topic in my AP Physics 1 class tomorrow (Fri., 9/11). Just started vector components after having taught graphical vector addition.
When explaining what a vector is, I explain that a magnitude is a 'how much' and the direction is the 'which way' the 'how much' acts. Using two 10 letter words to define a 6 letter word doesn't necessarily improve understanding.
Another good resource on trig and vectors is the Mechanical Universe episode (#7?) On vectors available here on UA-cam.
Love it girlie. I'm taking time out of my day to show my 4 nieces your show. THANKS
I never saw an answer to the problems. It means that most of the viewers are not learning at all. It is so basic, if you learned the concept of Trigonometry when you were 5 years old... Happy watching.
Yes Dianna, you make physics fun. So many cool things you can do and figure out!. Now I know how those laser distance calculators can tell you how tall a building is by pointing at the top.
I remember Sine is Opposite / Hypotenuse and Cosine is Adjacent / Hypotenuse because S and O come after C and A in the alphabet, respectively.
Thanks for this video. My 7th graders, that are rocking math, always start getting trig functions when they take adaptive tests. Now I can direct them to this a couple weeks before and win any bragging rights they can👍
Where can I get the answers? I solved the problems and really want to check them
1:41 A line IS a triangle with one angle of pi and zero for the other two
I just realized who you are reminding me of... my old Algebra I teacher I had in 8th grade. It isn't that she taught a lot of trigonometry, but in how she taught. She would use an overhead projector with a scrolling loop of celophane that she would write on so that she could go back to previous things she had done if need be, etc. The way you are writing on these pieces of poster board remind me of that. Your presentation by voice and humor also remind me of her. I never really learned acronyms like SohCahToa, etc. because I just don't learn that way... I have different methods for remembering the trig rules like this... basically two rules: Tangent is opposite over adjacent, and TAN=SIN/COS. From those two rules, you can derive the rest.
sin0° = 0
opp/hypotenuse = x/y
=0 since x(opp side) equals to 0 means adjacent concides
with hypotenuse
You may want to memorize the approximations: 0.000, 0.500, 0.707, 0.866, and 1.000. The ones ending in 0 are exact.
36.8699°, to be more precise.
1:55 To be clear: the angles of a TWO-DIMENSIONAL triangle always add up to 180.
of a *flat triangle.
triangles on curved surfaces are still, of themselves, 2D even if the space they embed must be 3D.
@@JNCressey Imagine starting on the north side pole, going south to the equator, moving 1/4th easth and then back to the north pole. Those are 3 x 90° angles and an equilateral triangle.
@@jaypaans3471, yes. I know. A sphere is a curved surface. And while the space a sphere is embedded in must be at least 3D, there surface of a sphere, itself, is 2D.
@@JNCressey if that were true, then they would defy the whole 180° rule, so it can't be true.
@@jaypaans3471, Two dimension surfaces: the sphere: ua-cam.com/video/5j0ZxkcVwhk/v-deo.html
Teacher Dianna, where were you in the time past when slide rules ruled. Only could manage a basic handle on to use it. Have learned more from you in a few lessons than 4 years of mathematics. Thanks Teacher Dianna.
One tool you didn't bring to the table was a sine bar. It's a flat bar with round parts at each end, like a little car whose wheels don't turn. It's used by putting a stack of blocks under one of the round parts, while leaving the other round part on the table. This makes a triangle of the height of the stack of blocks, the table, and the line between the bottoms of the two circles. Since the length of that line is the same regardless of how the bar is tipped, the angle of the bar to the table is the sine of the size of the stack divided by the fixed length. This lets you get any exact angle if you've got exact blocks and a table of sines, and if you can remember what the tool is called, you'll remember that sine is opposite over hypotenuse.
Why didn't anyone ever teach me that sin 30 is root 1 over 2 and that sin of 90 is root 4 over 2 instead of 1/2 and 1 respectively? I know they are the same, but now the pattern mak a sense (in a way the Unit Circle never did)!
Well, unit circle is really nice, but I agree that the pattern is much nicer with the roots making sense.
btw sin 0 is root 0 over 2 (insert MINDBLOWN meme)
Thank you so much i am struggling in physics as a high school student and you helped me so much!
After 40 plus years as a manufacturing machinist and CNC programmer I still struggle with Trig every day. I have no concept of what it is to be so clever that some find this stuff easy. Dianna did not explain this well but most of our modern world runs on Trig. GPS would be useless without this sort of math. I just enjoyed watching someone who is so excited about a subject I dread.
I love the video. You explained it really well and made it look so simple. I understand it a lot better now
At 07:00, why didnt she take tangent? she could have find the opposite side from their as well..🤔
Does anybody knows the answers of those 3 exercise ?
I got answers of problem sets as follows:
1. Opposite(NORTH) = 2.83 ( I applied sin45 ), EAST(cos45) = 2.83
2. Problem 2:
What component of that force is up ? => DON'T KNOW THE ANSWER
How much of it sideways, parallel to the sideways, parallel to the water? Ans. is (opposite/sin60°=) 1039.23N
3.
What is the angle of your resulting velocity vector ? => DON'T KNOW THE ANSWER
How fast are you swimming over the riverbed ? => DON'T KNOW THE ANSWER
Please correct me.
I know but don't have time. Feeling sleepy. Tell you tomorrow😴😴😴
I got the same answers as you for the first two questions but you forgot to add the answer for the horizontal force of the kite which I found to be 600N.
Its like going back to highschool. (Never understood this in Highschool. Loved the video and understood the concept. Would like more of these videos)
Great teacher!! I happened to see your channel by chance and it is great.
So many high school memories came flooding back..
Whenever Dianna refers to the tools had me cracking up.. lol :-)
It helps me to think about cosine as how far away it is (x-axis) and sine as how high it is (y-axis) from the measured angle.
Another great lesson from our very own Physics Girl! Aha! Waiting for your next lesson! 💗💗
Perfect timing, I am about to have a test on this topic in a few days! We just learned about how to use trigonometry in projectile motion, so this really helps! I must study aaaaaaaa.
Hi Dianna,
I have a doubt, can you pls solve it?
Why don't we place the aircraft engine above the aircraft's wings? Because the high speed air will flow above the wing and hence due to cavitation be pulled up and therefore create more lift. Can you please tell why don't we place the propellers above the wings?
Love the show and the the way you portray the information. Keep up the awsome work! By the way where can I score that swet hoodie?!
So even though the musical group One Direction was vector at one point in time, they all split up with different vectors (directions) later on? I wonder if momentum was conserved?
Oh, punny Dianna! Glad to see and here you again!
Can anyone please tell me that what I should use to convert my 220V ac supply to DC current with a voltage of my own choice????
😕😕😕😕
And is it okay to use DC in the coil to produce magnetic field.??
10:50 but the negative downward force would be upward force really.
If the hand is holding steady it would have to be applying the same force towards the person and upward, but the leash itself is pulling down on the hand, not upward.
@@emersonpropst2886 Exactly, the leash is pulling down so the *downward* force should be positive. The Fy force can be negative, if the y is pointing up, but then it is a negative _upward_ force really.
@@NetAndyCz I see what you are saying. My assumption was that she set the coordinates with x being positive toward the dog from the person, and y being positive upward starting at the ground (which at least in my high school and college physics classes was the default)
@@emersonpropst2886 Yeah, it is the usual default, the Fy is negative (and the actual direction of the force is downward). It is just weird and imho wrong to say that the _downward_ force is negative...
@@NetAndyCz that is a very good point, I hadn't thought about it that way and you are right.
Soh Cah Toa. good to hear it again. Good for calculating shadow angles for solar.
Wish you had drawn a unit circle to explain what sine and cosine really mean, rather than triangle ratios that happen to arise from them. Some people think it needlessly complicates things but I find it's much easier to grasp when you know what's really happening.
It’s a nice place to study the room and the clothes and the vibe
You really hammered those pun home. Loved every minute!
Shirt is smartly illustrated. My guess is it is a gift. You are the best teacher
Dianna, if you were an ANT in the top right corner of a rectangular room measuring 10 foot high by 15 feet wide by 20 feet long, what is the shortest distance to the diametrically opposed corner on the ground and you are an ANT and need to crawl there, what is the shortest distance, on the interior surface?
1:41 and 1:46 isn't it the same triangle with angles 90 90 0 ? So every line is an infinitely tall triangle, right? hehe
Wondering how, given a real situation and not drawings, how do you get the measurements to fill the formulae. How do you measure a dog's pull while walking, the wind's pull while more surfing, etc.
Loving applied physics.
A spring scale for these first two.
I always preffered the explanation of sin and cos using the unit circle. Where sin is just the y-koordinat and cos is the x-koordinat.
Thank you Dianna. I wanna say you have no idea how much this is appreciated, but I think you do.
Also, heard a lot of good bands play at SOHCAHTOA.
sin and cos have been complete mysteries for me until today. Thanks. (I'm 44 years old and went to public school.)
Awesome! My sister made me a hooded longsleeve shirt with that same Physics print fabric when I got my Physics degree😍.
Thx a lottt diana this series is fire🔥❤️
In India we mostly take the value of sin 45 as 1/√2, so when Diana wrote it as √2/2 I got bit confused 😅😅
Anyways great class as it refreshed my memory.
Thanks a lot Diana, really appreciate it❤️❤️
It is a convention that with simple fractions like that, you do not have a root in the denominator.
@@michaelsommers2356 Exactly!!!
It makes things easier to calculate. I should have thought that
Wow 😳 I always wondered was cos, sin, and tan meant on my calculator! Thanks Diana!!! I love it!
Oh, I hated trig, we had a unit in my geometry class, and they tried to make me, a dyslexic person who can barely remember a phone number, memorize the whole conversion table, I failed so badly that I failed the whole year of geometry, where I had been an A-B student for the rest of the year with almost no effort at all.
There are two ways of teaching this, and the way that emphasises triangles never worked with me. I know this stuff quite well, but thinking about it in terms of ratios of the lengths of the sides of a triangle is not intuitive to me.
Looking at in terms of a circle makes a lot more sense to me me. All of a sudden I can easily remember which function does what. For example, tan is the slope of the tangent of point on the circle. Cos and sin are the x and y coordinates of the point in cartesian coordinates.
Perhaps it's my programmer mind that prefers this description, but I'm pretty sure I'm not the only one given the number of times I've heard people having problems with intuitively understanding this.
I really love the way, you try to catch the marker.
Lots of love from India ❤
I even forgot when I subscribe to this Chanel. Is the first notification that UA-cam send me.
Diana sis we use BASE PERPENDICULAR HYPOTENUSE.... 😘😘