Introduction to tension | Forces and Newton's laws of motion | Physics

Introduction to tension | Forces and Newton's laws of motion | Physics | Khan Academy

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16 жыл бұрын

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An introduction to tension. Solving for the tension(s) in a set of wires when a weight is hanging from them. Created by Sal Khan.
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Physics on Khan Academy: Physics is the study of the basic principles that govern the physical world around us. We'll start by looking at motion itself. Then, we'll learn about forces, momentum, energy, and other concepts in lots of different physical situations. To get the most out of physics, you'll need a solid understanding of algebra and a basic understanding of trigonometry.
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Пікірлер: 324

@deiu9999 10 жыл бұрын

Wow, wow, I never knew all these concepts are so logical and I guess that`s the problem with most of nowadays teachers, they just fill the table wih formulas without telling us where it all came from... But you sir, you mannage to do this and I must say: "Thank you a lot, sir!" :)

@manasmarathe9579 5 жыл бұрын

There is no formula for this

@josephjithu8484 5 жыл бұрын

If Einstein had studied like that he would not be Einstein bud, he would be another brick in the wall

@victorprentice1062 6 жыл бұрын

AP Physics got me like “A student is going to hang himself because of the overwhelming topic that he fails every test and paper in. He is trying to find a rope that can support his weight. The student weighs 50kg. What is the tension of the rope?”

@libertax9213 5 жыл бұрын

There is no tension because there is no rope.

@crazykraken55 5 жыл бұрын

400N (100N loss of brain cells)

@annabeladesousa2692 5 жыл бұрын

The minimum tension that the rope can experience is 490 N,thus the tension will be 490 N upwards.(equilibrium)

@rubinakausar9559 5 жыл бұрын

Victor Prentice I agree with you

@snehalkancharlawar315 5 жыл бұрын

Thats actually me rn, im so dead and tired, ugh

@suchasrinagam7265 3 жыл бұрын

The fact that i got better notes here than my online class makes me wanna quit school and learn everything here!

@enderf4515 Жыл бұрын

umm..... probably a bad idea

@kingofstuff1732 Жыл бұрын

@@enderf4515 honestly I agree with them, my teacher is not good at teaching, at this point I'm pretty much doing self-study for ap physics

@top10swithtopaza40 Жыл бұрын

This is 15 years old now, but it's still better than the material I get in school, thank you so much Khan academy

@awesomealf79 Жыл бұрын

Heh true

@YourFriendDevin 5 жыл бұрын

I’m heading over right now to fix that gap in the green line

@how-toplaygames4987 6 жыл бұрын

its been 10 years, and im still watching this

@nickboldan7833 9 жыл бұрын

Very well explained. Tension can seem like some abstract thing, but it's really just a force, and often students aren't made aware of that until they see real-life examples.

@add5955 12 жыл бұрын

I get the concept of tension well, seeing how I get it everyday sitting in a Physics classroom

@TunaNoCrust305 11 жыл бұрын

For future reference, at 8:50, to solve T1 1/2= 100, you have to get the T alone. So to do that you have to cancel out the 1/2 and the way to do that is to do the opposite of division, because 1/2 you are dividing, if you were multiplying you would divide, so you multiply with the recipricle of 1/2 which is 2. So what you do to one side you do to the other, 2 * 100 = 200. T=200

@aqualife88 Жыл бұрын

KCF keep change flip lol

@22kuter 8 жыл бұрын

Thanks, this lifted my stress as my teacher didn't explain it very well, and this explains it in such a simple way, thanks

@kundai5265 7 жыл бұрын

Thank you for this! made perfect sense for once

@galachoxy 14 жыл бұрын

Ur a great teacher,,,,u make it simple and clear unlike my teacher in physics who just make get a hard time in solving a tension n' frictions,,i like it so much...thanks a lot from timor-lete..

@pushpanarayanpur 4 жыл бұрын

Thank you so much. Excellent explanation!

@hppaviliona1700la 13 жыл бұрын

Please make a video of this but with an angle in the T2! Your videos help me a lot, thanks!

@SSTube80 15 жыл бұрын

you are the man for doing this, thank you!

@DeMonYitOoO 11 жыл бұрын

Thank YOU!!! SO MUCH!! YOU HELPED ME ALOT I HAVE A TEST ON WEDNESDAY THANYOU SO MUCH!! ILOVEYOU!

@soumyajoshi176 3 жыл бұрын

2012 Khan academy, here I am in 2021

@Ahfjo 11 жыл бұрын

I always wondered does the maximum tension of a rope change depending on the length of the rope? Obviously, the material of the rope has to be the same in both cases, but can longer rope hold more weight than a shorter rope?

@bhargav7215 3 жыл бұрын

Depends on the force exerted...

@arjungathwala8217 6 жыл бұрын

Great video! Sal is the real man 🐉

@derciobene3458 9 жыл бұрын

Thanks a lot for your good work

@SafeAndEffectiveTheySaid 15 жыл бұрын

What this guy do is a really good job. If you can help someone out, you are a good person. But if you help people all over the world, you are like an angel.

@protopug_ Жыл бұрын

wow This comment was written when I was 13

@SafeAndEffectiveTheySaid Жыл бұрын

@@protopug_ times flies. Hope you enjoy your college time as much as I did.

@protopug_ Жыл бұрын

@@SafeAndEffectiveTheySaid wow, didn't expect to get such a quick reply and thank you for your wishes

@ranindunimesh4036 11 ай бұрын

@@SafeAndEffectiveTheySaid how are you doing now?

@sc00biedoo 11 жыл бұрын

this is fantastic!

@seavech 13 жыл бұрын

thnx a lot!!! now i am ready for the test that i have in an hour!!! THNX A LOT

@janeeyre9076 3 жыл бұрын

Thank you. It was very Helpfull🙏

@olivermathiasen3594 Жыл бұрын

Very well explained. Didnt understand the last part. But ill rewatch after some sleep. Hopefully it will get in then.

@pirate1406 8 жыл бұрын

Could you make a video with a problem that has a string with mass? Thanks

@Master1906 12 жыл бұрын

You are completely correct. As sin(angle) approaches 0, the number becomes infinitely small, in other worlds, [100N]/[Very small number ] = Extremely large number. So at 0 degrees, in order to keep the string taut under the weight, it will require infinite tension no matter how small the weight is. Think about this. Get a string. Make it horizontal and straight. It will NEVER be perfectly straight and taut due to gravity pulling the middle section down, no matter how hard you tense it.

@xxminaxcoladaxx 13 жыл бұрын

Brilliant....really clear and helpful thank you. I have a forces test on Monday and you've really helped to refresh my memory!

@CEMAGC 3 жыл бұрын

did you get an A+?

@boniquer931 2 жыл бұрын

@@CEMAGC bro he passed the whole thing from 11 yrs lmao

@janahsabriyamacapundag3448 6 ай бұрын

WOW I LOVE THIS

@Dan4157 14 жыл бұрын

but good sir, that makes too much damn sense!

@shamimjaved8714 7 жыл бұрын

its very helpfull for students

@lazaruz01 7 жыл бұрын

Haha! SOH CAH TOA in blood red. Like the blood in my nose when I couldn't get this topic when I was in high school

@bobross3356 7 жыл бұрын

Jera Angeles lol

@ankejkumar1120 7 жыл бұрын

Family tension

@zahidahmadzai8023 6 жыл бұрын

Ur forehead is bigger than my entire future

@mr.knowitall5019 3 жыл бұрын

Spaced repetition

@BrentonaBike 10 жыл бұрын

Can you do a video in regards to vertical cables with pretension and horizontal forces?

@XH1tokiriX 15 жыл бұрын

great way to study for mid-terms. Thx!! =]

@BarbarosZeren 2 жыл бұрын

Wow 12 years ago. I wonder what are you doing right know.

@XH1tokiriX 2 жыл бұрын

@@BarbarosZeren I don't even know how you found a 12 year old comment!! I'm a police officer now, fell a little short of my scientist goal loool

@BarbarosZeren 2 жыл бұрын

@@XH1tokiriX I hope you are doing great. I wish you the best.

@AtlasJS 12 жыл бұрын

@grandprix1110 i realized why i was getting the question wrong... the calculator wasn't in degrees, so each time i would use sine and cosine the answer would be wrong because my calculator wasn't on the degrees setting... FML

@abhishekutkarsh 12 жыл бұрын

you are great !!!!

@Nguyening_music 13 жыл бұрын

Professor, can you do that WHOLE problem again for me? Professor: HELLLLLL TO THE NO! youtube: sure click replay :)

@ankuraks3919 3 жыл бұрын

9 year old comment 😨😨

@cdgod616 3 жыл бұрын

@@ankuraks3919 10 now lol

@tricklander87 20 күн бұрын

@@ankuraks39193 year old reply😭

@fozanshaque6094 4 жыл бұрын

awesome explaination

@QuicklimeProductions 11 жыл бұрын

I think the force is distributed throughout the whole rope so it could, like how a larger pot of water take more heat to boil because the thermal energy is distributed through more water, a larger rope has more area to distribute the force so it could handle greater forces before breaking. Idk for sure though...

@kaldorei58 3 жыл бұрын

Such a classic we have here.

@jfmarque 13 жыл бұрын

Could you please explain an example using an angle as unknown?

@IQ-rl2wx 4 жыл бұрын

Such important concepts

@muhammadadel191 10 жыл бұрын

woooondeeeerfuuul >> Bless you!

@priyanshusobti9935 6 жыл бұрын

thnx sir I was never able to solve complicated tension problems befor watching this👍

@ajaysvlog9958 Ай бұрын

Its been 6years boy

@Hunnymuffin321 11 жыл бұрын

@rnichols16 that gets confusing for me too, but if you we're to multiply 100 by (1/2) it would be 50, but you were dividing in this case. 100/(1/2) is the same as 100 times the reciprocal of (1/2) which is 2.

@Abril-ge8uq 4 жыл бұрын

I'm watching this and my midterm exam is tomorrow

@ibrahimmahmoud7714 4 жыл бұрын

Same

@alizayrehan4849 3 жыл бұрын

Same

@iwannacommitjisatsu5858 3 жыл бұрын

Same, I'm having a midlife crisis rn. I'm gonna fail Sci ngl

@gerrenx7 13 жыл бұрын

Bless you sir

@USMChiLD 15 жыл бұрын

Thanks Sal.

@khalidfaiz8735 7 жыл бұрын

bro your videos are the best

@fefafe334 13 жыл бұрын

his favorite word is "intuitive" .. lolx!

@nidaaa7714 6 жыл бұрын

many thankkkkss

@benihana360 11 жыл бұрын

thank you so much!!!!!

@Papaabe 5 жыл бұрын

when the string breaks will the particle move a distance before hitting the ground, please I need a quick answer

@legoindianajones1000 12 жыл бұрын

So how do you involve calc in physics? Integration? Derivs?

@lalali451 4 жыл бұрын

Thank you sir 👍👌

@serenavue4254 7 жыл бұрын

How did you know what equation to use to find the T1x component?

@carlybutler9190 11 жыл бұрын

Thankyou!!! I have a test tomorrow and this is perfectt!!

@7clouds567 2 жыл бұрын

Hey there... this seems 9 year old... What are you doing now?

@ghuolxgaming7603 Жыл бұрын

Yea same question

@niceguy4801 3 жыл бұрын

Thankyou sir

@asteroides8204 11 жыл бұрын

can i just say, I LOVE YOU. I WISH YOU WERE MY TEACHER

@yc9928 5 жыл бұрын

Thx teacher khan

@cubesolver 16 жыл бұрын

I like how the 30 degree angle is larger than the 60 degree angle

@ua24986 15 жыл бұрын

he always says, "I'll see you in the next video" but actually only talk to us, I wish he showed his face...I would like to see this professor!

@ajaysvlog9958 Ай бұрын

15 yrs nice

@emmafrankly 13 жыл бұрын

So does T1 include the blue string directly above the object?

@phanidruva 8 жыл бұрын

Since the body is stationary, the sum of all forces is equal to zero? Is it so?

@aragonification 8 жыл бұрын

Since the body isn't accelerating*, I think.

@aragonification 8 жыл бұрын

Since the body isn't accelerating*, I think.

@lazaruz01 7 жыл бұрын

It's the idea...Equilibrium should mean that the object is not accelerating and to the that all the forces must be equal to zero either to keep the object stationary or moving in a constant motion.

@sanaakhan6273 6 жыл бұрын

yes, it is in equilibrium

@muhammadjawadaslam9020 5 жыл бұрын

Hmmm... I think if you do not consider the rotation velcoity of earth then yeah, but since the direction of rotation is constantly changing then velcoity of earth is constantly changing, therefore it exerts its effect onto us, but since the system and us observing it have the same velcoity at every point on the Earth s surface, we say it's in equilibrium, as we consider that velocity as constant.

@UltimateSAB 12 жыл бұрын

thanks!!!!!!

@ibraheemmonks8866 3 жыл бұрын

Which pixel is the string?

@uralegend123 12 жыл бұрын

Finally, this is the first time I've seen trigonometry in application

@jigneshshah6134 6 жыл бұрын

tysm sir

@wrestlewithmagic123 6 жыл бұрын

why cos 30 only was taken in the last step...

@Yaj-kk4is Жыл бұрын

nice

@Shivastorm88 12 жыл бұрын

You, sir, are a God amongst MEN!

@TheKmanOfSmash 12 жыл бұрын

So with a 100N weight and the angle T1 makes being 30 degrees, the tension in the T1 string is 200N (100/(sin30) = 100N/(1/2) = (2)(100N) = 200N). I understand that. Now, this happens to be double the weight of the original weight (100N). Does this mean that as the angles T1 makes approaches 0 degrees (horizontal), the tension in the T1 string approaches infinity? If so or not, why? And if so, why is the tension in T2 not infinity by this logic?

@funkyboy_22 8 жыл бұрын

Audio's pretty bad. In middle volume, I can hardly hear anything.

@meatmissile8229 6 жыл бұрын

This video made me understand this concept a lot better. I do have a question though. Sal used a triangle to the right of the T_1y vector. Couldn't he have used the same triangle on the other side of the vector where the side parallel to the y component would've been straight up from the weight? The angle is the same as he stated, and the use of sin is still the same because the y component is still the opposite side from the angle.

@sunritroykarmakar4406 6 жыл бұрын

Meat Missile yes but the second part of the question would have become more complicated. it is the same really

@trailertrashtactics 5 жыл бұрын

anybody else notice that the intro to this video compared to the ending of the last sounded like Sal was recording in his closet trying not to wake up his wife and kid XD. This guy is seriously incredible though.

@seifdeiab 11 жыл бұрын

Why we did not use sin60*?

@jojogirl2008 11 жыл бұрын

why are the pulley videos private?!

@myworld-si8zk 7 жыл бұрын

good

@A591m 4 жыл бұрын

this video made me realize this was really the easiest thing ever but why did it seem like such a messy and horrible thing to learn during class.... lol

@arpangoswami2333 8 жыл бұрын

you are good

@alientechgaming7521 7 жыл бұрын

What about spring tension

@NishieFernandez 13 жыл бұрын

it's dat easy? ;) thx man

@sangitaaditya4505 6 жыл бұрын

Can anyone explain how is that angle 30 degrees?

@megaelliott 15 жыл бұрын

He does that to try to give people intuition.

@FastKid26 11 жыл бұрын

YES WE KHAN

@Thesashi7 11 жыл бұрын

How do you get the net force(T1 + T2 + T3 )? I tried but this doesn't give me 0. what's wrong?

@AimlessZealot 12 жыл бұрын

Physics is full of calc: Uniform Force = (mass)x(acceleration), and (acceleration) = (Rate of change of velocity)... Anyone taking basic calc (derivatives) recognizes "Rate of change" meaning "Derivative of". Momentum = (mass)(velocity) and Kinetic Energy = (1/2)(mass)(velocity)^2. Users of integral calc recognize that w/ constant mass (both equations are), kinetic energy=integral of momentum. Physics is full of calc, but if you don't know calc you can memorize and muddle through.

@and1fer 10 жыл бұрын

well those are some thick fuggin lines

@AtlasJS 12 жыл бұрын

@sk8rlt Thats where the problem is i understand the concept yet i don't know what is going on that im getting wrong. I love math and one of the reasons is that i've realized that in math if i get an answer wrong i can just retrace my steps and find that one small addition error or maybe a negative sign i forgot to place at some point or another, but in physics that's not the case. I can't seem to find any errors in what i'm doing and therers so many steps its just overwhelming.

@youknowwhatimtalkingabout 5 ай бұрын

6:40 'SOH CAH TOA in blood red'

@baretings1 12 жыл бұрын

would you call the tension the reaction force of the weight of the block? or is it a seperate force and will have its own reaction force?

@khabibconor1566 4 жыл бұрын

no its reaction force i hope i was helpful

@pal1531 5 ай бұрын

W explanation

@pjtheman1 14 жыл бұрын

the reason he used trig is to help apply the concept of conceptual thinking and help you understand whats going on and why the things work- the pythagorean theorem would be able to do that - but that would get the right answer- but good thinking bkisme

@LookingAtYou_ Ай бұрын

no wayyy!!! i can see these views are getting higher when I keep looking at the views count for a 16 years old video!

@michaelpalomino6239 7 жыл бұрын

how is that angle 30 degree's? I always thought that the angle closest to the 90 degree angle is 60 degrees and the angle farthest makes the 30 degree angle.

@sunritroykarmakar4406 6 жыл бұрын

Michael Palomino no.

@tantalides 14 жыл бұрын

isn't some of the tension distributed to the bottom string in the second problem?

@Pamplemousse89 13 жыл бұрын

@martmelee It is EXACTLY THE SAME for me! :(

@crzyaznpistonsfan 12 жыл бұрын

He sounded incredibly ominous in the beginning of the video. "I will now introduce you to the concept of tension...muahahahaha."

@Jeromebefit 12 жыл бұрын

I thought it was pretty good. Do another problem where something is hanging from one string and then it has a rope attached to the left 15 degree below the horizontal and then a rope from the right with a 25 degree angle. The tension on the rope to the left is 500N. Whats the tension on the 25 degree rope? Something like that.