Hello and welcome to another GCSE PE related video. Today I'm going to run through a GCSE PE video that's targeted towards this year's examinations. And please, before we begin, do not forget to subscribe to the channel and hit the notification bell. So to begin with...
I would like to discuss the different parts that make up each of the lever systems you can see. So you have a fulcrum which can also be known as the pivot, you have the resistance which can also be known as the load and you have the effort. I like to stick with the words fulcrum, resistance and effort because I like to use something called F R E 1 2 3 and what that simply means is The fulcrum sits centrally of a first class lever system.
So that being my F. R, resistance sits centrally of my second class lever system. And then finally, E, effort sits centrally of my third class lever system. So F, R, E, 1, 2, 3. What you also need to know is when you're asked to draw a lever system, You have to draw an arrow to represent the effort, you have to draw a square to represent the resistance and you have to draw a triangle to represent the fulcrum. Now moving on from that, if we have a look at the first class lever system we need to start thinking about sporting examples associated with it.
So a couple of examples that I might mention are movement of the neck forwards and backwards and in that particular scenario the fulcrum will be the joint that sits just behind the jawbone. The effort will be the muscles in the neck and the resistance will be the weight of the head. If I were to give you another example for a first class lever system we might talk about a tricep extension or a football throw. So in that particular situation the fulcrum will be the elbow because that's the joint, that's where the movement occurs.
The tricep would be the effort because that's the muscle that contracts and produces the movement. and the resistance would be either the dumbbell that I'm using or the football that I'm throwing. For a second class lever system we might start to look at the ankle in different scenarios. So you could look at a calf raise, you could look at the starting position when exploding out of the blocks in 100 meter sprints, you could also look at running in general. So the fulcrum would be the actual ball of the foot where we see the crease in a person's trainer that would be the fulcrum because that acts as the joint the effort would be the muscle in the lower leg located at the back which is known as the gastrocnemius i'm sure you understand that and resistance would be the person's body weight for a third class lever system we'd start to look at something like a bicep curl so in this scenario the effort will be the bicep because it's the muscle that contracts and shortens causing the movement to take place place.
The fulcrum will be the joint, which is the elbow, and then the resistance will be the dumbbell, the weight that the person is lifting as they perform the exercise. And let's move on to mechanical advantage. So a second class lever system has a mechanical advantage. And the reason being is that the resistance arm is short.
This basically means that the distance between the resistance and the fulcrum is shorter than the distance. of the fulcrum and the effort. Okay, so there's a long effort arm here between the fulcrum and the effort. What that means is when you perform an exercise like a calf raise, the input force, which is the effort, is actually minimal, but the output force is great. So if I were to ask you to perform a calf raise now, I'm sure you know from experience it's quite an easy exercise to perform, and therefore it requires minimal effort.
but the outcome is great because it moves the entire body. And moving on to a third class lever system, it has a mechanical disadvantage because unlike the second class lever system, it has a short effort arm instead of long. So the distance between the fulcrum and the effort is short, but the resistance arm is long.
So the fulcrum and resistance are further apart. So for that reason, it has a mechanical disadvantage. Thank you for joining me.
I hope you found it helpful. Good luck in your exams this year and please, please, please, if you do have any questions or concerns, please just share them in the comment section below. I am more than happy to help. Thanks for joining me.
Take care. See you again soon.