Conservation of angular momemtum

[Kratos6798]

this video was great

[mufc4everch]

Did he do any problems with this?

[clairslyy]

omg instead of "ω" he said "w"

my physics teacher would kill him hahaha

[freddy21421]

Take all of my money.

[1105iTube]

the continuous fidgeting is really annoying. still a great help, though. thanks

[rahulj1994]

thanks a lot finally i got it>>

thankyou

[daniellua1]

Is there any video in which he talks about Moment of inertia and deducts the cylinder, ring,sphere expressions ?

Thanks you

Keep bringing the physics!!!!!

[breeogie]

Holy crap, I understand this!!

[MrRockit98]

I swear I'm in year 7 and Ian learning stuff that even year 10 don't know. You are awesome!!

[I3urningi3laze]

You misspelled momentum by using "m" instead of "n" in the title. Just felt like pointing that out... but good video though, keep up the good work!

[Kroberter]

i take college classes on youtube for free and i actually learn but never get the depression after a bad exam

[TheSlimjones]

OK, i admit to being a complete mental midget when it comes to this stuff. And I'm only here because of an idea I had and im trying to see it its correct. Mind you I've not gone any further in math than algebra. But, if the distance on this teaching was the distance of earth from the sun, and gravity was the arm and and were in an expanding universe shouldnt the earth be traveling away from the sun and therefor slowing down in rotation? Sorry for my ignorance here. Im sure it's a dumb ? to most

[joejacksonriley]

it is not doubleyou, it is actually omega.

[KuSarahB]

why does the torque not change when you change the radius "=length of the arm!" :/ :S

[robx0r]

@KuSarahB He is talking about conservation of momentum. In order for momentum to be conserved, there must be a net torque of 0 applied. If torque is zero, and you change the radius, something must give. In this case, when r is shortened, angular velocity increases to pick up the slack.

[salv02]

@KuSarahB because it only changes torque depending on the distance from the axis the force is being applied at

[samsafisher]

@KuSarahB Because the force used to pull the arm in (Sal said retractable) is parallel to the moment arm. Torque only occurs when a force has a component perpendicular to the moment arm.

[Keh0ol]

@KuSarahB there is no energy added to the system thus the torque doesn't change

[Keh0ol]

@Keh0ol mean to say "the momentum doesn't change"

there is no torque in his last picture obviously :D

[snuffle1]

My college physics class makes me shell out thousands of dollars then hands me worksheets and says "Teach yourself". Teacher doesnt even lecture. Why am I learning more from Youtube videos???

[maxsmell]

let's pool together money to buy this man a tablet pen :) amazing lectures, but distracting scribbles :p

[misterman567]

omega...

[jioddon]

dude... u deserve sum serious award...

[decamike1]

You know what's weird... I'm not even paying you $5,000 a semseter for this.

[leeo268]

You taught me physic 20 time faster than my college class, Thank you

[PoseLucas]

Torque is mad 1:20

[RTRVII]

you go wrong in the first line i'm sorry. Its a vector equation for one, and the direction of the torque is defined to be perpendicular on the plain where the force and the distance vectors are in.

Good job though.

[nick16693]

YOU are definitely the best!! really! I'm italian and I've understood better with your explanation than my teacher's one!!!

[cauvongkhuyet7]

oh nvm i see why, different objects have different inertia so nvm i get it >.<

[cauvongkhuyet7]

can you explain why angular momentum is mwr^2 because L=Iw and I=.5mr^2 so isn't it suppose to be L=.5mwr^2? im soooo confused on this one

[matchxCx]

really really amazing work !

[Marteena13]

Sal I love you. I never knew why when they pulled there arms in they spin faster..

[izi2bhappy]

WAY TO GO!

[MichaelisOnYourtube]

yessssss,,,once agaaain.haha

everyone tell everyone about this site!

its the bomb!

[MRJerrod410]

What happened to the moment of inertia?

wmr^2 = wI where I = the moment of inertia.

[conve4521]

@MRJerrod410 the moment of  inertia is mr^2, which was a quantity that he used. he used moi, but just didnt tell us.

[samGenius4]

even though im doing maths degree im having to do so much physics n thanx to these videos im learning things in 10mins that would normally have taken 2 hrs!!!

a million thanx from the uk

[megaelliott]

Great video thank you. 8:46, you sounded really posh.

[imkelly901]

THANK YOUU!!!!!!

[tutts3131]

think about your units in this case. you have your radius in feet. simply switch it to meters, and why do u never refer to angular momentum in terms of I*w, or m*v*r??

[RUjyosei]

I agree but I still enjoyed it

[chandin69]

thanks this is just awesome

[Aeaglegirl67]

thank u so much

[firemist23]

I'm in love...

[xlwaiyiplx]

???

[firemist23]

lol this video just helped me A LOT when I needed it xD so much that I fell in love..

[psychox4]

great video, keep posting

[Discernement]

nice vid