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Simple Machines (1 of 7) Pulleys; Defining Forces, Distances and MA, Part 1

Feb 23, 2020
Well, in today's video I'm going to go over the following terms for

simple

machines

and how they relate directly to

pulleys

, one of the most common types of

simple

machines

, especially if you're in school. Well, we have the input force, the input distance, the output. force the ascending distance and the mechanical advantage those are the five terms as I say, those are the five terms that we are going to review well and this is how it works this is the pulley machine these are the

pulleys

this is a simple machine we have one pulley two cops three pulleys and four pulleys normally when we have them grouped we think of this is like the top pulley the two and then this bottom pulley this is the rope that we would pull and this is the object starts here, let's raise it up to here, okay, then The first thing and perhaps the simplest is that the output force is the weight of the object we are trying to lift and is measured in Newtons if you measure your weight. in the metric system you measure it in Newtons and the weight of the object you mean the weight of the object is the output force, that is the force that you are trying to get out of the machine that you want to lift, that is the force that we are trying to get exit and we usually draw one that points downward because the force points downwards to the output force and is equal to the weight, so if someone said in a problem oh, we were trying to lift an object with a weight of 20 Newtons, that is the output force in this case, so we have the input force, which is the force that you put into the machine, that's why they call it input force and it's usually just the force that you apply to the rope when you pull on it. string you have one of those spring scales you attach it to the end and you pull and that is the input force that is the force that you put in this is the force that you are trying to get out this is the force that you put in the machine it is also measured in Newtons , okay, so we have the exit distance OD, which is the distance that the object is ready, that's what you're trying to get out of the machine, you're trying to raise it a certain distance, that's what you want to get out , that's why it's called exit distance, it's the distance that the object moves up because in this case you want to move this up, so let's go from here to here, that's the exit distance, then we have the entry distance , well, the input distance is the distance that the rope actually moves when you pull the rope, you pull it up in this case and you pull it so far the distance that you pulled that is the distance that you put in that is the input distance okay and that would be true and the

distances

that should be measured in meters are sometimes measured in centimeters, but in reality they should measure the base unit for the metric system, which is the meter, so those are the four terms output force and input force i F, that is what is measured with the scale, the spring scale.
simple machines 1 of 7 pulleys defining forces distances and ma part 1
The exit distance is the OD, which is the distance the object is raised and the entry distance is how far you pull the rope. Well, you should be familiar with those four terms and how they relate to police. Okay, now let's review what the mechanical advantage is. Alright, the mechanical advantage knot has kind of a technical definition or a technical sounding definition, but I think the best one I found is the factor by which the simple machine multiplies the input force and really with simple machines we want to be able to put more force to go in, excuse me, less force to go in and take out more force, that's why we use a simple machine, if we want to be able to lift something that's a hundred Newtons, we don't want to have to use 100 Newtons of force, okay?
simple machines 1 of 7 pulleys defining forces distances and ma part 1

More Interesting Facts About,

simple machines 1 of 7 pulleys defining forces distances and ma part 1...

I will go over some problem and solve it, but it is the force, it is the factor by which the simple machine multiplies the input force to give us the output force. Now there are two equations, the mechanical advantage MA can be found by taking the force output. and divide it by the input force or you can take the mechanical advantage is equal to the input distance divided by the output distance the mechanical advantage is a unitless number because the

forces

or

distances

will cancel well now for pulleys and only for pulleys because that's the only one that actually has a string, you can determine the mechanical advantage by counting the number of strings that support the output force or that support the weight, then all we do is count the number of strings and this is what I mean we have our pulley system. over here we're going to oh yeah, but we want to find out what the MA is we're going to find out what the MA is we just count the number string the way we do it we just look in the middle between the two pulleys how many ropes they're supporting because actually this rope supports the weight this rope supports the weight this rope supports the weight and this rope supports the weight so you just look, you count and you get in this case the mechanical advantage of this pulley system is four, so this pulley system is going to multiply the input force by four, so, for example, if we put 20 Newtons on the scale, we pull the rope, the input force with 20 Newtons we will be able to lift an object that has a weight. of 80 Newtons we're going to multiply the input force by a factor of four just count the number of strings okay so this is a quick video going over those four terms output input input output distances and

forces

and mechanical advantage in the next video we'll actually do some calculations where we calculate some of the forces and distances.
simple machines 1 of 7 pulleys defining forces distances and ma part 1
Well, thank you very much for watching. I hope you found it useful. If you found this helpful, you can give me a thumbs up or leave me a comment in the comments section below. thank you
simple machines 1 of 7 pulleys defining forces distances and ma part 1

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