Atwood's Machine Problems

[@joy8386]

14 years later and you are still helping students, thanks!!

[@pokeroguetrash]

You are the first person who has made any sense explaining this to me. Great video, thank you for helping

[@amr-bw4gf]

You taught me more in 8 minutes than my teacher could in 3 weeks

[@qasmcbraylov6963]

So agreee

[@Normalguythatisbored]

Fr

[@b3a3n3a3n3a3s]

Never seen the masses drawn out in a straight line like that and now a lot of confusion has been lifted, thank you very much.

[@thecalazoneh4917]

Oh my god dude your a lifesaver, I actually understood this better from your 8 minute video then my teachers 40 minute lecture XD

[@michaeljulias209]

@@beyza1624 yea i don't know where he got that also

[@dylanzuke5124]

You’re*

[@robiulahmed]

This is the most lucid explanation I've seen regarding Attwood machine physics. Every other video gets bogged down with maths. Thank you. Truly.

[@w7geek]

Lasse, I hope you still read the comments, because you need to know how awesome you are. Thank you!

[@seans5096]

10 years later and this guy is still saving lives

[@youssefabdelhamid2336]

Very nice picture you drew at 7:20 good job sir.

[@thy7917]

+Youssef Abdelhamid had me dying..

[@theguitarkid5402]

Saw that in my notes while reviewing my parents looked at me like I was an idiot

[@parkertyson5757]

So sad he didn't draw the center of the pulley

[@mahhattaheen]

Legend!!

[@beyza1624]

@@parkertyson5757 but how did we find the 20N and 30N ?? why multiply with 10?

[@davidhickey1084]

just going into my dynamics exam and I see this...this is brilliant, makes perfect sense and works brilliantly, sound!

[@instaminox]

i was failing this course, there is a lot of videos on youtube that confuses us a lot however...now that I found you ... my hope increased exponentially. best wishes.

[@lilac749]

This helped so much! This cleared up my questions while studying for the MCAT!

[@headtroma325]

Holy crap! I've been battling this problem all night and I finally understand it, Thanks for the video :)

[@rakanalmana6509]

Thank you so much for this video! This really helped me understand this machine before my exam I have on Physics.

[@Slantedpine]

Faxxxxxxxxxx

[@ELewis-rk4wf]

Thank you very much. My text's explanation of the Atwood machine was incomprehensible and then I found you. You integrate the algebraic approach to solving the problem with the use of numbers and make the problem easy to solve. Thanks a lot. I'll check out your other videos now.

[@mikemwila2076]

this guy is really good at this ; this is his second video Am benefiting from and adding to my favorites videos now . Already subscribed !

[@mithushanbalendran8593]

even after 10 years of this video being out its da best

[@ladybuggirl112]

this helped me so much. I’m a slow learner and have a lot of trouble with math but this was so easy to understand! Thank you!!

[@borcf1557]

when you placed the two mass horzintal, nd said the string is one pice that conncets two masses helped so much thank you

[@toaotou]

the introduction is a bit long but the later explanations are really clear! thanks a lot

[@ashleequintanilla3396]

WOW watching this in 2018 and now everything makes sense god bless your soul

[@cherrylady1234567]

Could not understand pulley system problems until I saw this, thank you :')

[@sprocket609]

Thank you so much! my teacher didn't explain this type of problem very well. I'm not confused any more!

[@Inggybaby99]

OHMYGOD!!! This is like the best video ever ! I have my physics final in a few days and you are a lifesaver! thank you so much! xD

[@superpiggy1071]

Thanks so much I have a test for physics tomorrow and now I actually have an idea of what to do

[@InvadingChihuahuas]

You've helped me a lot in AP Physics, thanks!

[@mr6462]

thank you very much ! this video helped me understanding this test and the tension , but i'm still a little bit confused by the tension force. Due to Newton's third law , the forces are paired and equal, so when both of m1 and m2 are trying to get each other down, what should tension force be depended on? For instance,when m1 is trying to get down, it also get the reaction force from m2. When m2 is trying to get m1 down , it would probably get the reaction force from m1, lol. I'm just confused , hope to hear from you.

[@trollmasta4873]

wow! you are awesone 😄 glad i found this channel right before my midterms...

[@abhiisnotme]

this is amazing, i never knew i would understand this until I watched the video, thanks for your help!

[@sophiajager2699]

Great explanation! You saved me from failing my exam tomorrow.

[@katherinechen1473]

Thank you for making this so simple to understand!

[@amyth9004]

One of the best physics series

[@cookiemuenster]

Tension is a force and forces are vectors, so if something is accelerating in the direction that a string is pulling, acceleration and tension will be the same.

[@jacksawhavoc]

that's the best explanation for why you do this the way you do that I have ever heard and I have heard a lot of them

[@teeheejejo]

It became clearer for me, I checked rotational dynamics part III, and noticed that atwood's is a bit simpler than of the problem that the pulley is massive.

[@ladypotato.9876]

You are a lifesaver! I can't thank you enough!! I now understand this

[@queenjessicathefirst]

YOU ARE A GENIUS SIR I HAVE AN AP TEST IN 2 DAYS

[@roberthensley7130]

Nice! Now I'll be ready for my lab tomorrow.

[@thomasjoliveau8318]

so helpful. Better than my teacher's explanation

[@Stacey-r8p]

Thank you a lot! Helped with exam preparation:)

[@TheNetworkGenius]

You make things so simple. Thank you

[@benjaminwilliams2741]

I tried to apply the Atwood Machine in the field at my job. I have to carry my 50 pound backpack up and down a 175' tower. So I thought to create an Atwood Machine using a 200' rope, two pulleys, my backpack(M1) and some weights(M2). The objective was to establish equilibrium so that I could easily take my backpack up and down the tower with little to no effort. My atwood machine failed miserably. I was able to raise my backpack (lowering the weights) with very little effort. But lowering my backpack (raising the weights) took a tremendous amount of effort - there had to have been at least 25lbs of resistance when lowering my backpack. I'm baffled in how it worked one way but not the other.

[@skillet137]

Thank you so much! This video is so incredibly helpful (and easy to follow).

[@PrinceAdom]

okay, can you explain how you got had m2 in the denominiator to be positive? I had a negative m2. I used the technique of summation of forces along the y-axis.

[@Hbrand03]

i am so late but thank you for helping us find tension, ur brilliant

[@thepandagamer5331]

Thanks for the help! Definitely saved my grade!

[@lasseviren1]

See the above description of the video for the answer to your question. I just added more text to it so that it addressed your question more directly. Thanks.

[@isberg1995]

Thanks a lot! If my teacher would have explained it like this, i would'nt have to spend hour after hour, trying to solve these problems by myself.

[@devinrhines1250]

Thank you!!! My teacher didn't even teach us this but decides to put this on the midterm smh.

[@Druidicalism]

thank you so, so, so much! our provided (ripoff) textbook is of no use in working through problems like this. thank you for your time and contribution to public education!

[@Adiibak]

You are a true Physics Hero.

[@jityr2]

At 0:58 it's easy to assume that the acceleration would be greater for the system on the right because m1 is on a level surface instead of hanging down. The system on the left has m1 hanging down., which makes it easy to assume that the acceleration would be slower. Would such assumptions be right?

[@teeheejejo]

Isn't the radius of the pulley important in such cases? And when would the mass of the pulley be affecting my system?

[@maximumride886]

Why did it take my teacher 2 weeks to teach this and I still didn't understand, but I watch this and its like, bam! Understand

[@shabasupermayn]

I rarely see this method much simpler than the one we are taught, where we use way more messy looking algebra

[@StickElite]

yeah i agree, i'm in highschool physics and we were taught ma= fa- fw -ft+ ft -fw which is basically the same but way more confusing this video helped a lot

[@erikbeier9515]

Well explained and precisely demonstrated.

[@MyBilal19971]

Why can't I use the equatn Ft-mg=Fnet? Because Ft is pointing upward(Assumed +ve) and mg is pointing downward(Assumed -ve) if we are to take the vector direction in mind.

[@crazyforcats19]

How would you find the apparent weight of the 3-kg mass? Is that equal to the tension?

[@lasseviren1]

Usually apparent weight is a normal force but for this set up the apparent weight would be the force of tension on the suspended mass.

[@crazyforcats19]

@@lasseviren1 That was quick! Thank you so much!

[@Bakugantsuvai1]

Could we have pulley problems like these with friction please?

[@Paivimehr]

Clear explanation. Thanks. Like Lasse Viren. I am from Finland..

[@nicolesaed]

What if the mass of the pulley has to be taken in consideration?

[@lasseviren1]

The following video details that situation: Rotational Dynamics (part III)

[@Bethebug123]

The problem I'm working on doesn't give the tension forces for each weight (or either weight)

[@moronguillo]

since there are two weights, shouldn't there be two tensions also, one for m1 and one for m2?

[@Notadoc22]

@ymxyy0313 i think he is stating that the acceleration of gravity is roughly 10m/s^2 so the resulting force is 20N and 30N repectively

[@aamirmateen2002]

why is the tension same of unequal masses plz explain in detail.

[@amr-bw4gf]

It’s very simple. they are the same rope so tension is same everywhere on the rope

[@pierresstargirl]

finally, I understand how to do these problems :D

[@GodlessNfree]

Nice vid but i got a question i cant seem to figure out... so for my questions the givens are m1=5kg Ft= 78.4 and a=5.9m/s the unknown is m2.. it seems so simple but i cant get it together, think u could give me a formula??

[@finom97]

@genkers He was assuming the gravity was 10 m/s^2, so 2kg had a force of 20 N, 3 kg, had a force of 30 N

[@notloc8993]

How is it that the tension is the same throughout the rope of different weights are acting on it

[@lasseviren1]

For different scenarios the tension will vary but for a given scenario the tension will be the same throughout the rope. This is only true if the rope's mass is negligible and the pulley's mass is negligible or the rope slides across the pulley with no friction.

[@lasseviren1]

I know this did not answer your question but I just wanted to clarify what I meant by saying, "the tension will be the same throughout the rope."

[@notloc8993]

I understand that now . I’m just trying to figure out if there’s a formula to prove this or if there’s a visual way to show this

[@lasseviren1]

@@notloc8993 I'm on a trip but when I get home in a few days, I'll make a video to answer your question. For now, imagine breaking the rope into 100 little segments. Segment 2 pulls on segment 1 (s1) with the same force that s1 pulls on s2 because of Newton's 3rd law. Now if s2 has an almost zero mass then the net force on it would be m*a which would be almost 0 because m is 0. That means that the force of s1 on s2 has to be almost equal to the force of s3 on s2. Next we say that the force of s2 on s3 is equal to the force of s3 on s2 because of the 3rd law. And so on down the rope. You can see why a video would be easier than typing this in the comments.

[@lasseviren1]

Keep analyzing each segment of rope using Newton's 3rd and Newton's 2nd law all the way down the rope.

[@ApostleOfDub]

How do you come to the conclusion that 3kg box has a 30N force and the 2kg box has a 20N force? Did you just round the acceleration of gravity from 9.81 to 10 and multiply that by the mass? Or should the force down on each box be given? Thanks.

[@sea5205]

joe he rounded 9.81 to 10

[@Torchfang]

How did you get 24 n!

[@jonathansanchez8802]

love these lectures!

[@aschmidt570]

You just blew my mind. thank you!

[@venkatamaheshmunagala9918]

Is large mass body decide the tension in spring if it does please explain.

[@lasseviren1]

Both masses affect the tension in the string. Once you know the acceleration of the system (by analyzing both masses), then you can use either mass and Newton's 2nd law to determine the tension in the string.

[@hollyphant]

It is MiNd BlOwInG how easily you explained this to me wtf, I suck at physics dude but this is so easy now lmao

[@hafsahkhan16]

I am so glad I found this

[@rickytian1007]

What if you put this whole system inside an elevator which is accelerating upwards?

[@lasseviren1]

If the elevator were accelerating upward at 2 m/s/s then it is equivalent to being on a planet with a g of (9.8+2)m/s/s. So you do the same problem but use 11.8 m/s/s. If it were accelerating downward at 2 m/s/s then you would use (9.8 - 2)m/s/s. In other words if the elevator were in free fall, then the system wouldn't move relative to the elevator (9.8 - 9.8)m/s/s or 0 m/s/s. Of course I haven't told you why this is the case. I would need to make a video to do so.

[@taters1123]

Watch carefully from 5:24 to 5:41. He gets the value for acceleration, which he plugs into his tension formula to solve for force tension.

[@donepearce]

What is the value of g where you live? It seems to be quite a bit different round here.

[@erikmjelde4428]

what about torque in the pulley?

[@reetisafui776]

Thank you so very much! It was of great help!

[@ymxyy0313]

how did he get the 20n and the 30n, or did he jsut make that up?

[@sea5205]

tlyang he rounded 9.81 to 10 and then x by the mass to get the weight (force)

[@manasvijain8304]

Wow this helped me so much. Thank you

[@adelaidecanada]

This helped sooooooo much!!!! Thank-you!

[@genkers]

what if i dont know the forces pulling on it?

[@vinayabhat6006]

Thank you so much! it finally makes sense!!

[@physicswithramzeen2386]

Thank you, Well Explanation...

[@sea5205]

Great video!

[@k123mc]

how did he get 24N??????????

[@taeyang]

this guy can teach!!!!!

[@maixiong9650]

Wow, how do you make it so easy when I am pulling my hair out!

[@rachelkong1039]

Thanks! It's really help me!!

[@AbdulKhaleed]

Honestly, thank you so much.

[@ahmedzs1]

Great explanation thanks so much.

[@Ruba1006]

Thank you sir - from Norway

[@raavirohith3113]

can u give the proof of a at 4:29 min

[@tauqirpashas8359]

thank u soo much for posting this video...

[@Actkara_Vlogs]

how are you getting 24?

[@Actkara_Vlogs]

nevermind i figured it out, haha

[@carlo4145]

can someone tell me how did he get the 6N in 6:46

[@lasseviren1]

I multiplied both sides of the equation by 3 kg. So... (2m/s/s)(3kg) = 30N - Ft which then becomes 6N=30N - Ft.

[@H223Tommy]

The forces are gravity * mass. In this video he simplified gravity to be 10 Hence - Force on the smaller wieght = 10 * 2Kg = 20N