Moments | Moments, torque, and angular momentum | Physics | Khan Academy
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- Опубликовано: 5 сен 2024
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Introduction to moments. Created by Sal Khan.
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*Clockwise:*
↩️
*Counter clockwise:*
↪️
Hope this helped
Edit: (1 year later) Did i seriously just tell people on the internet what clockwise and counterclockwise is?? LMAO
Seriously? But thanks for the good Intent
Boris take away tax innit
Cant you just think about a clock in your head.
@@itsjustanapple5452 for people who were born in the digital age and never seen a ⏰ they'll find this really helpful
Here I am a year later laughing at what you said. LMAO
he confuses clockwise and anticlockwise in the end but overall he explains everything else perfectly
Tryna be my tutor? 😏
He did correct it in the end..He noticed it
@@zolanhlangulela947 he said “confuses” not wrong
I came here to see if I was crazy. I was so confused, lol
"It always becomes a lot easier when you do a problem, except when you try to erase things with GREEN."
8 years ago and someone is probably seeing your comment for the first time
9 now and I was just the 5th person to like it
4:29
Nico, are you still there, how old are you
Eesa Salman Kakakhel 18 years .. you?
I hope this and all other physics videos gets updated to HD and have all their mistakes fixed. I'm still loving KA though and will keep donating!
did he cnfused on clockwise n anticlockwise?
Yess omg i was so confused
yep
+Amira Lam. hi
Yes i think he did
I mean he did, but he clarified the method we should use for this type of problems! 😂
"why did I write down mechanical?" lol. His unintentional humor makes it really fun to watch.
How did life treat you? How was school?
though it is helpful
but presentor have confusion in clockwise and anticlockwise
Nobody:
Comments: keeps saying he confused between clockwise and counter clockwise non stop
Note: am I the only one who writes/says anti clockwise rather than counter clockwise?
Moment is simply just a rotating force around a specific point/pivot. You can start with this simple meaning
You literally are my physics exam savior
Hilarious how you know all this detailed physics stuff yet can't figure out which way a clock-hand moves.
Great video though, very helpful!
QUESTION - Any explanation of "moment" or "moment connections" must start with the etymology of the term "moment" which is crucial for me when I try to understand anything. So any layperson, when they think of the term "moment" is in reference to time. A "moment" of time. So now that we are apparently repurposing the term "moment" for torque etc can you explain why it is called a "moment" to begin with? How is the term "moment" in reference to time used here or are we redefining the term specifically for physics / Engineering?
The day that you can torque better than Miley Cyrus
+Kun Seung Lee better than Rihanna
+Clara “mylove2345” Torque Torque Torque Torque Torque he said me haffi TorqueTorqueTorqueTorqueTorque! xD
True that Mr Obama
Sal, you are great. Just a little correction: Im afraid that you did confuse the clock- and counter clockwise directions at about 10 minutes. But Its common sense. Best regards from Serbia
twerk.......... now im understanding moments of a force!! thank you Khan
oh my gosh I was 4 when this video came out, now I'm in college and this guy has helped me get through calculus, chemistry, and physics many many times. thank you sir you have been a blessing in my life
basically the closer the object is to the pivot... the more effort ( force ) required ?
Hello Sir! I have a question regarding the direction of a force. How can I determine if a force is clockwise or counterclockwise? Could you please provide some guidance or resources on this topic? Thank you in advance for your help!
very nice, this is a review for me but your confusion of counter-clockwise / clockwise every now and then is funny, making the tutorial quite refresh and not sleepy
"i don't know... lets say its 2 " - damn , did i laugh so much :)
guys he mentions that he kept mixing up clockwise with counterclockwise near the end just go with clockwise and counterclockwise as you would. he was just mixing them up on accident
Sal...you are the man. Thank you.
for the last time,
clockwise = --> this way
counter clockwise=
@vladuz1001 Always remember this formula: F=ma where 'F' is measured in Newtons(N), 'm' is measured in Kilograms(Kg) and 'a' is measured is Metres per second squard(M/s^2). 'a' is usually 9.8m/s^2 when you're talking about forces acting perpendicular to a surface. If we apply F=ma to your problem:
1,294(N)=m(Kg)x9.8(m/s^2)
You're trying to find the mass, or 'm', so we divide both sides by 9.8 to make 'm' the subject.
1,294/9.8=m
Therefore m=132Kg
god bless khan academy
oof almost a million people saw sal getting confused with clockwise and counter clockwise xD
if you view the same video on the ka website a small pop up corrects his mistake
I got it ......and, as a teacher myself, I have some sympathy for the guy here. Some days are just harder than others. LOL.
You say clockwise and counterclockwise backwards at 11:00. But thank you for the great video[s]!
Good Video, Confused about The CCW and CW parts until you corrected it at the end. But still very helpful
this. was. twelve. dang. years. ago.
and yet his way teaching never fails to teach me : )
until he messes up counterclockwise and clockwise. Still its all love
Look its easy, just think about trigonometry: your angle is positive as it goes counterclockwise and negative as it's going clockwise. if you can just keep that image in your head, everything becomes pretty straightforward as far as the direction of torque goes.
mate in a short video ive learnt more from you than my physics teacher.... you made it so easy to explain..
How is that counter-clockwise ?
because we get +ve value of F .. and initially we assumed that it will be in counter-clockwise
Lifesaver. About to write a test and you have no idea how much confusion you saved me from. @MdHussain
😊😊
I don't get, and I have a test next week. Help pls!!! @Md Hussain
How'd your test go? And just for advice: keep searching on UTube & you'll find success. X''S
U explain so nicely and clearly
The explanation is very comprehensible and we'll simplified, but the video is only available in low resolution..
Excellent teaching style. Thanks.
wonderful and a highly conceptual video......simply amazing......like ittttttt....!!!
You're amazing for refreshing my pre-university memory keep it up :D
Its actually really nice thanks
you're just overreacting
Hey Sal, I've been looking at dozens of videos and wikipedia pages, but I can't find a formal proof for why M = Fr. Can you do a video describing the formal proof behind this formula? Cheers
its not angular momentum its troque
for angular momentum it will be momentum times the radius
oh my god, thank you, thank you, thank you.
If the sum of anticlockwise moments and clockwise moments are not in equilibrium and I want to find a particular force can I do this, for example:
20F - 5(10g) - 10(10g) - 15(10g) = ma?
20, 5, 10, 15 are distances from the pivot in metres, and m = mass, a = acceleration.
@goldensilverstar He corrects himself at 13:36 but the concept gets across if you don't get stuck on that one detail.
i was confused in your video.. please make it better and correct for the next time around.. Thank you..
he just mixed up everything through out the video and he corrected it as from the 13:21 ,coz if you actually take a clock and try to compare the movement of the forces with the clock hands' mov'ts,you will realize that the 10N and 50N forces actually move in a ''CLOCKWISE'' direction,and the 5N ,6N, F forces go ''ANTICLOCKWISE or COUNTER CLOCKWISE''...hope this was helpful enough!!
RIP Clockwise and Counterclockwise.
angled ones u need to use cos or sin to calculate... and u can assume clockwise as any direction and counterclockwise as the opposite direction of the clockwise...
stop complaining, he is good
12:10 why are you multiplying the variable F with anti-clockwise moment 6*3?
Come on guys, understanding the graph and method is wayyyyy better than complaining about clockwise and counterclockwise, this this case, u just need to know the force direction is different and put them in opposite side of the equation.
Thank God! I'm so happy Dr. Khan made a video!!
Thanks Sal, I remember I was terrible @ this stuff in high school. Now I'm at university and I need to know this stuff for a Biomechanics unit, so much clearer now.
your better at teaching than my science teacher
omg the clockwise and counterclockwise stuff was so frustrating. here's a simple trick, clockwise goes in the same direction that a clock moves. lol.
Brilliant explanation. We got the clockwise/anti-clockwise, thanks again! 👍
11:00 24N*8ft would work very nicely.
Sal I think you may have just saved my life! THANKS SOO MUCH!
It was easy for me to understand because i saw your comment prior to watching :D
How do you determine the unknown force as clockwise or anticlockwise? Or you just assume
@vladuz1001 m.g=1,294 N where g (the gravitational force =9.8 m/sec^2 ) so divide the force by g to get the mass
I'd love to see a lot of beam deflection problems using calculus. Simple span two point beams with multiple loads and cantilevers - but not all at once. Thanks so much love your work!
Same with me, I really am having problems about the rotation, whether its a C or a CC.
Dear Salman , plz dont bother that you clouded the directions in the last case. Know that you're an amazing teacher and we love you a lot.
Ah! I sure wish I found this channel earlier! But thanks too anyway.
he made me pass my grade 9 exam now im doing my BIG School leaving Exams lets see if he'll do the job now
8 years later, how are you doing man??
just use right hand rule for the sign convention of clockwise and counterclockwise. I finished this in half the time it took time to explain
take a shot every time Sal mixes clockwise and counter-clockwise
There's a problem with rotation direction but the computation is correct since it is to be equated to zero for the system to be in equilibrium.
finally I undesrstood thanks Sal
thanks, this helped alot :)
THANK YOU SO MUCH....
@jamieskill. 10 is an estimate for g. Since 10 is much easier to use mathematically it makes sense to round to 10 instead of multiplying or dividing everything by 9.81, especially if taking a test without a calculator.
plz are you sure about what u said in your Example < clockwise and counter clockwise >!!!! I think you reflected the trends ........who is agree with me?
+Taj Alhashem as long as you are consistent with your direction, the result would not really matter.
he's wrong .. that's not counterclock wise
clock was screwed and so the directions
i
Me too
If I screwed up a video explaining a simple concept such as this as badly as this guy did I would re-do it.
Please make an HD video of this
Clockwise = "-" and CCW = "+"are just conventions. Just like we consider "up" to be "+" - who decided that?...These questions work even if you assume clockwise as "+", as long as you are consistant. Every Teacher/Instructor/Prof will teach the concept slightly differently. Best to keep perspective and take these concepts and apply them to your course notes. Yes, he did mess up he clockwise and CCW, but he is hardly the first to do it - Draw good FBD, assume forces and use Equilibrium equations
Would you do a presentation on torque created on a archery shot where the hand meets the bow?
i still don't get the cw and the ccw because how is this direction ---> counterclockwise? isn't that clockwise?
God bless you Sal....I have a nephew who looks like you btw
thanks a lot for the video. great help to students like me.
You still alive?
Thanks a lot!
In the second example, i don't get it why would 10N upward force thats on the right termed as anti clockwise 🤔
What do I do if anti clockwise is larger than clockwise and not in equilibrium
@diamond3187 When that happens its the up loader of the video flipping it to avoid copyright detection.
that's not counter clockwise 😒
For all of you guys confused wondering if he got clockwise and counter-clockwise mixed up, he didn't. That's how torque works.
Oh shoot! I gotta watch this!
I'm so lost @ my Engr. Mechanics right now and I don't get the magnitude of the moments stuff!
thanks bro!, you helped me a lot, keep up the good work!!!
LOL dude! Nice lesson! I actually learn a lot + it is fun. I love it, thanks a lot, I got a hard time understand this.
it really helped me in some points but when he pointed the clockwise and counterclockwise ...
thanks dude
Thank you so much!
thanks a lot.
thanx mate!
How do u know if the unknown force is clockwise or counterclockwise
this was very good.. i get it now!!lol.. im in 10th grade and when im studyings physics for exams this is so helpful!! thanks=)
Well its like making mistakes while teaching really works i totally get it now 😆 🤣
whatever.. Khan Academy is the best for physics
dude you're amazing i love this!
Hilarious how he mixes up counter clockwise and clockwise, even when he acknowledges he's done it!! :)
oh thnx god, this video save my live!!!
When you are teaching a complex problem and you are writing on a table and you have a lot of writing errors at what point do you stop writing and start over? Suggestion, if you look at the screen and get confused, your students/audience will be even more confused. I have dyslexia and your written presentation looks my note taking, and I can't read them either :-)