How Pulleys Work

[Zergling924]

thank you so much for this video - it has helped me immensely in teaching a student of mine! (i don't happen to have a pulley system on hand for demonstrations, haha)

[MrMoneymeister]

Yay!

[runr100]

Nicely done...perhaps you could add more pulleys?

[whitebelt23]

thank you very much!

[paramo81]

i had a question, so if you take the extra dumbell you had at the beggining of the video, and attatched it to the pull end of the rope 2 feet up, will the 1 lb of wieght actually lift the load of the 1 lb dumbell, seeing as how it only takes a 1/2 pound to lift it? this might be a good visual point to make in the future?

[charliemarz]

@paramo81 Yes a one pound weight would lift the one pound load. In fact any weight slightly larger than one half pound would lift the one pound load.

[zealandzen]

Great video. Succinct. Good visuals. Repetition of facts is key. Much appreicated. Let's see more science videos like this one.

[oppression99]

excellent video.

[armybradarmy]

This was a simple but very good video to the point.  My son is in grade four and needs a project on pullys.....This explained everything to get him on the right track. Myself as well. Thanks. Tavistock Ont

[Vamperlis]

and 2. People say that the fixed pulley up top is ONLY to allow you to pull down rather than pull up. But it seems to me, that if that fixed pulley were attached by a thread----a very very very tiny thread, strong enough to hold only the weight of the pulley---then when you put the rope over that pulley and pull down, I imagine that the thread holding the pulley would break. That would reason that the fixed pulley is supporting the load at least a little. Am I wrong??

[charliemarz]

@Vamperlis

I believe that the fixed pulley does exert a force on whatever is supporting it.

However, no motion and therefore no work is associated with this pulley.

[byproxy97]

@Vamperlis i agree with you. the fixed pulley would support a little of the weight, but I think mainly it is to redirect the pulling. Which is exactly the use of a single fixed pulley, redirecting force. But ya, either way I think it supports a fraction of the weight, but it would only matter on a larger scale.

[Vamperlis]

Thank you for the video, but I have 2 questions for you:

1. The impression I get is that the reason you can use less force when you use a moveable pulley is because half of the weight is supported by the fixed end of the string. BUT, imagine that you turn a pulley horizontally. For instance, maybe one end of a rope is attached to a wall, and there is a giant boulder that the rope goes behind and you have the other end of the rope. Why would it give you a mechanical advantage here?

[charliemarz]

@Vamperlis

In this case, the force we are working against is friction. No force is is

exerted on either side of the rope until you start pulling. Once you start

pulling there will be tension on the side of rope you are holding as well the

rope attached to the wall. The force on the boulder is the sum of these two

tensions. If you pull the rope a distance of two feet, the boulder will only

move one foot.

[WillChandler27]

thanks mate :)

[emery50adam]

Good job!

[TreblinkaUnderscore]

Thank you for taking the time to educate. Very simple and clear. I appreciate it.

[kezznlott]

omg this video is really goood...thanks :)

[Wiegieboard]

I'm loving this video. Thanks for making it. Fantastic.

[50cliber]

english plz

[ilovearmadillos]

@50cliber Be less retard plz

[ymartini1]

The first time EVER that I've actually understood this mechanism. Thank you.

[larubiamasmala23]

Is there any way that I can email you? We are trying to build a display like you did but I have no clue how to do so.

[charliemarz]

@larubiamasmala23

Thanks for your interest. I would be happy to help you. My e-mail address is

cmarzzacco@aol.com

Charlie

[ajdc88]

This is the best explanation of how pulleys work I've found on YouTube. Thanks!

[ukidding]

why not add 1/2 pound weight onto the 'pulled" string and see it lift the 1 lb weight 1 foot into the air

[ukidding]

why not add 1/2 pound weight onto the 'pulled" string and see it move the 1 lb weight throught 1 foot of movement

[MrFryfish]

Very nice and clear. Thank you!

[sonidoeterno]

I was wondering exactly how pulleys worked for a while and now it makes as LOT more sense. Thank you for your explanation charliemarz!

[Stempiooo]

thanks sir!

[I8pikachu]

Good job.

[jts112]

perfect!

[arayan83079]

Thank you for the explanation. I am an arborist and I use pulleys all the time. I can't quite "explain" how they work, but I sure can put them to work!

Thanks for making me better at explaining it.

[BuddyAMP]

Appreciated sir!

[mundapunda]

that was very helpful for my sister's school project

[Keyfaze]

Cool