Love having to watch a RUclips video on physics because my teacher teaches us the most limited information needed to do basic problems then says "these ones are harder so dont take them lightly" and doesnt explain how to do them. Then she gets mad at us when we fail her tests
Love your Channel ! In preparation of my last exam I used your videos for what I didn't fully understood, end result? I got 70% and the average of the class is 40% Next exam Monday and I'm definitely watching your videos prior to it ! Thank you very much Khan Academy
Having this, I was able to do a problem where there was a force at theta, and had to calculate for an adjusted F_n in order to find the blocks kinetic acceleration. A great help thank you!
5:23 "I could do that in my head, I shouldn't have to look at that." One of the cons of a calculator. Because we live in such an era: Thank you for the lecture!
Thank you Mr. Khan you just clarified the way the different coefficients work! The static friction doesn't change the initial force when you go to calculate the Fnet concerning the kinetic friction (i.e. you subtract 26.95 from 100, not 70.6. I suppose one has to know if the force is constant, which most of the time it is for beginning physics problems.
Thank you!!! Thank you!!!! Thank you!!!!! My teacher skipped the fundamentals and even the common equations and straight to the compound questions..... You are a great help!!
Sal, you have no idea what it feels like to have this fog of confusion (which started in high school) finally clearing after a couple decades. Thank you.
While this is a good, well explained example; it is fairly trivial in nature. To be fair, this example does give a great introduction to a very puzzling topic of physics, but from the comments below there is a mixture of responses as to who truly understands this topic, who is still confused, and who is still lost on this topic. If there was a way to tie the concepts presented in this video to a more complex problem or present them in more diverse situations to give those who are still struggling different views on how to interpret when to use the coefficient of static friction versus when to use the coefficient of kinetic friction, then I think this topic would be more understood by all.
no. static will always be larger. just think about the static friction coefficient as being the threshold, that must be overcome, then kinetic is easier to push, hence its lower coefficient.
well if you have the acceleration you can work it out, use v = u + at to get final velocity half it (assuming it starts stationary) to get the average velocity and s = vt to get s = (at / 2)t use that to work out t then use that value of t in v = u + at
Thank you so much. One question though. Car physics. If 100N (theoretically) was applied to another car, of 5kg and they stuck together, would the total acceleration be f=ma. 73.05 = mass of both cars/a ?
isn't Fb the budging force? so why is it used as the friction force? i thought it was like the minimum force needed to overcome the static friction INSTEAD of the force of static friction itself.
What a great video.. Thanks a bunch. But i think to accelerate the load from rest, we need to overcome both the static and Kinetic Friction at the same time. which means, Fnet =//F//-Fstatic- Fkinetic= Ma 100-(29.4+26.95)=5a Please i need more explanation..
Regarding living in nonliving bonds between two objects or more are the charges of the frequencies to strengthen this coefficient. Are there any other forces involved regarding communication between two objects?
How would you work out how much time it takes for the force static friction to be overcome? You've calculated acceleration, but there's zero displacement. I feel like the answer is obvious but it's alluding me atm. :x
Thanks, but how do you find kinetic when the object is on horizontal plane that is 14 degrees above the ground, and all you are given is the weight in Newtons?
So how do we calculate the jerk from the moment the force is applied to when it moves? It looks like the change is from 14.1 to 14.6. So is it just simple simple subtraction?
On extrasmooth surface .. All the surface molecules on the bodies are in contact ... Resulting in increased intermolecular attraction ... Which leads to more friction
Tryna find out how to solve uk and us. Ik the formula is uk=fk/fn and us=fs,max/fn. but idk how to plug numbers in them, typically fk and fs,max. And apparently us is supposed to be greater than uk
Thank you. Physics can be so scary when your teachers talk at you a little, hands you a book, and says, "Do this."
I understood completely up until 1:12
Hahaa
1:12
Man you made me seriously like physics your awesome teacher :).
here's your like after 8 years :>>
@@highhyena7198 10 now
@@analien5479 17 now
89 now@@Drforeverok
@@son-gxku 99
Love having to watch a RUclips video on physics because my teacher teaches us the most limited information needed to do basic problems then says "these ones are harder so dont take them lightly" and doesnt explain how to do them. Then she gets mad at us when we fail her tests
Same.
why is your name donald trump
khan you are a life saver
Love your Channel !
In preparation of my last exam I used your videos for what I didn't fully understood, end result?
I got 70% and the average of the class is 40%
Next exam Monday and I'm definitely watching your videos prior to it !
Thank you very much Khan Academy
You are the sole reason i have an A in physics. Thank you so much
That block is moving pretty fast. There should be a follow-up problem where it crashes into something.
4:55 total =100 N, force needed to overcome F of static friction =29.4. Static friction
Thanks. Sir you make the subject so easy to understand. You are incredible! !!!!!!! You are the GOD of studies. I am totally mesmerised by you.
MiRaje8086 Who the fuck said Debasis Sahu was a guy?
MiRaje8086 How about no? Immature fool.
+Kevin Tang it's an indian name. debasis is a male.
Sukanya Dutta Well still, if he's a guy then why does it matter to him? He's probably just a dumb 12 year old kid who wants attention.
Learning physics with this is a life-saver. Thanks so Much!!!!
Having this, I was able to do a problem where there was a force at theta, and had to calculate for an adjusted F_n in order to find the blocks kinetic acceleration. A great help thank you!
Have a test on this for my AP Physics class in a few hours. This video was great. Feel ready now.
soooo.... how did it go?
@@highhyena7198 In short...badly. Probably studied for like 1 hour total which was a huge mistake. 6-8 total hours would have been perfect.
@@Dani98664 I'm a little bit surprised that you replied to me after four years, but it was nice knowing
@@highhyena7198 I still use this account a lot to watch videos and got a notification from your msg
@@Dani98664 lmao I have test on this and I missed 2 weeks
great lecture! my statics final is in 2 1/2 hours and I have officially been partially relieved of this confusion.
How did it go?
@@justsomeguyontheinternet5917i hope you know they commented this 11 years ago lool
u r a legend
Thanks. Sir the subject seems so easy after you explain. You are the GOD of studies . You are incredible!
khan u truly are a khan!!
Thanks :D I have a mid-term in an hour. Wish me luck!!!
Hey, how did ya do? It was five years ago, but how are you doing now? Is life treating you well? I hope you did well on that test.
5 years in the future me in the same situation
@@patrick7726 lol
No joke have one tomorrow. 6 years and we are still doing the same thing.
@@anoshtaraporevala9926 how did it go?
Really can't believe this whole academy has a one-man-army narrator and (not sure) teacher.
It’s the night before the exam. I’m very stressed. I cant wait to look back on this comment and moment in time in a few years 🥲
thanks for this opportunity to learn from the expert
have an IB Physics test in 24 hours. Thanks for making me understand this concept!!!
5:23 "I could do that in my head, I shouldn't have to look at that."
One of the cons of a calculator.
Because we live in such an era:
Thank you for the lecture!
Thx for saving me eight weeks.
Explained very well. Please explain about velocity triangles in turbines
Thank you Mr. Khan you just clarified the way the different coefficients work! The static friction doesn't change the initial force when you go to calculate the Fnet concerning the kinetic friction (i.e. you subtract 26.95 from 100, not 70.6. I suppose one has to know if the force is constant, which most of the time it is for beginning physics problems.
wow Sal is upgrading
HD now!
Thank you!!! Thank you!!!! Thank you!!!!! My teacher skipped the fundamentals and even the common equations and straight to the compound questions..... You are a great help!!
Sal, you have no idea what it feels like to have this fog of confusion (which started in high school) finally clearing after a couple decades. Thank you.
decades?
@@maenshraim263 Yeah. School was a long time ago for me.
Great explanation, makes a lot of sense now!
For those who don't understand why he is dividing it, F=M.A
ie. A(acceleration)=
F/M
This was excellent! Thank you!
Great video making Physics seems natural and simple. Khan Academy saves so many students....🏆
Hold on for Net force, don’t we deduct the force of friction and the force taken to overcome static friction from 100?
watching this before my exam tmr, wish me luck!
Pete Z goodluck
Pete Z good luck... friend
6 years later how was it?
very clear! you are good at explaining
VERY GOOD EXPLANATION ...THANK YOU!!
thank you so much !! i had an assignement but didnt understant really well in order to do it ans as always khan academy is the super hero
Thank u I have my paper TMR morning
While this is a good, well explained example; it is fairly trivial in nature. To be fair, this example does give a great introduction to a very puzzling topic of physics, but from the comments below there is a mixture of responses as to who truly understands this topic, who is still confused, and who is still lost on this topic. If there was a way to tie the concepts presented in this video to a more complex problem or present them in more diverse situations to give those who are still struggling different views on how to interpret when to use the coefficient of static friction versus when to use the coefficient of kinetic friction, then I think this topic would be more understood by all.
How did you find the coefficient ??
It is given in the question
no. static will always be larger. just think about the static friction coefficient as being the threshold, that must be overcome, then kinetic is easier to push, hence its lower coefficient.
Thank you so much, you're better than my Physics teacher, I wish I had you rather than him. Greeting from Mexico, I'm at a bilingual school c:
Is the "moment" your initial acceleration?
I having a quiz tomorrow you save me, Dang Thank You! I was having trouble with this thing
why does the more collinear the force applied and the frictional force against it, the tendency for toppling an object is is less?
Thank you, it helps a lot..
After seeing this I think I khan learn anything
Very helpful.
This is such a helpful video! Thank you so much :)
I hope I'd learn that . But somehow I've lots of idea with regard here. Thank you
This was so helpful!
Im a math major but physics is my first love. And first love never dies.
That was great!!!! Thanks. Can you do a similar example where it asks "what is the speed of the block after it has moved 3m?"
well if you have the acceleration you can work it out, use v = u + at to get final velocity half it (assuming it starts stationary) to get the average velocity and s = vt to get s = (at / 2)t use that to work out t then use that value of t in v = u + at
WOW YOU GUYS
FREEEE I CANT BELIEVE IT
I know, I am taking it now in 11 U Physics. It sound hard but it is kinda easy when you try some
Thank you, Sal...again and again. Do you realize the magnitude of your contributions to the developing of scientific thinking?
Pretty sure he does
Thank you so much. One question though. Car physics. If 100N (theoretically) was applied to another car, of 5kg and they stuck together, would the total acceleration be f=ma. 73.05 = mass of both cars/a ?
Sir, is running a machine a disadvantage or advantage of friction
well, that was AWESOME!!!!!!
Found this video in a Drum'n'bass playlist lol
isn't Fb the budging force? so why is it used as the friction force? i thought it was like the minimum force needed to overcome the static friction INSTEAD of the force of static friction itself.
What a great video.. Thanks a bunch.
But i think to accelerate the load from rest, we need to overcome both the static and Kinetic Friction at the same time. which means, Fnet =//F//-Fstatic- Fkinetic= Ma
100-(29.4+26.95)=5a
Please i need more explanation..
I thought the same
Regarding living in nonliving bonds between two objects or more are the charges of the frequencies to strengthen this coefficient. Are there any other forces involved regarding communication between two objects?
Great video, thanks.
How would you work out how much time it takes for the force static friction to be overcome? You've calculated acceleration, but there's zero displacement. I feel like the answer is obvious but it's alluding me atm. :x
I want to know what is coefficient of static and kentic friction !!! And why? I don't need to know how to use it.
Thank you so much for this.
You're creating more than complications
Thank you so much!
Awesome 👏
Thanks, but how do you find kinetic when the object is on horizontal plane that is 14 degrees above the ground, and all you are given is the weight in Newtons?
So how do we calculate the jerk from the moment the force is applied to when it moves? It looks like the change is from 14.1 to 14.6. So is it just simple simple subtraction?
Dearest Sal,
You saved my butt in chemistry, and it looks as though the story will repeat with physics.
Thanks :)
omg I don't get it physics is just confusing......
Same tbfh
@@novice6869 me too
@@lailymojnu5126 yeah, i think it's kinda easy
Thank you
You're awesome man!
Hail Sal!!
thank you alot sir
thanks
thank you so much. love from bangladesh
thank you sir
Hey sal thnx for amazing videos...
Hey why dont you add animation and vfx subjects?? Here in india ppl so unaware nd thinks its childish
Merci beaucoup monsieur :D
Hey, I'm learning French on Duolingo and I suppose this means "Thank you very much, sir". I just hope I'm right
thanks lot........
Thanks mate
but how LONG will it go to the right before it slows down??
thanks dude, just video and i finally understood this :)
Can someone tell me why does force of friction increases when surfaces in contact are extra smooth
On extrasmooth surface .. All the surface molecules on the bodies are in contact ... Resulting in increased intermolecular attraction ... Which leads to more friction
Beatsta thank so much for this information 😃😁
thanks to helps us
thank you very much. i finally understand this
Panic For Physics Final Mode : Deactivated!
So at the end, the force of friction acting on the object is 26.95 N????
Where is 9.8 kg that was multipled by 5kg from? Please explain more!🙏🏾
Can the coefficient of kinetic friction ever be greater than that of static friction?
no
You're awesome.
When you discuss I get it
When my teacher discuss
I don't get it
How long is "a moment"?
I love you sal khan
Tryna find out how to solve uk and us. Ik the formula is uk=fk/fn and us=fs,max/fn. but idk how to plug numbers in them, typically fk and fs,max. And apparently us is supposed to be greater than uk