• last year
Transcript
00:00hi kids today we will learn about effort arm and load arm of a lever and how to
00:10find its mechanical advantage so let's start we know lever has essentially
00:19three parts effort load and fulcrum and based on the position of effort load and
00:28fulcrum lever can be of three types class 1 class 2 and class 3 fulcrum in
00:39the center class 1 lever load in the center class 2 lever and effort in the
00:47center is class 3 lever now let's learn about the effort arm and load arm of the
00:56lever the arm joining the effort to the fulcrum is the effort arm or the
01:04distance between the effort and the fulcrum load arm the arm joining the
01:11load and the fulcrum or the distance between the load and the fulcrum is
01:16known as load arm and it's the length of the load arm and effort arm of the lever
01:24that decides the mechanical advantage of that type of lever now let's see the
01:33effort arm and load arm of different types of levers class 1 lever that has
01:41fulcrum in the center here this is the load arm of the lever that is the
01:49distance between the load and the fulcrum and this is effort arm of the
01:56lever that is the distance between the effort and the fulcrum remember the rule
02:03is the longer the effort arm the larger the mechanical advantage of the lever
02:10now let's learn it with examples here we have a class 1 lever this point is
02:18effort this is fulcrum and this is the load effort arm is the distance between
02:24the effort and the fulcrum so this much is the effort arm and load arm is the
02:32distance between the load and the fulcrum so this much is the load arm so
02:38you can clearly see over here that the effort arm is much longer than the load
02:44arm and the rule is the longer the effort arm the larger the mechanical
02:52advantage so this lever will give a large mechanical advantage now here is
02:59one more example here we have one more class 1 lever effort arm is the distance
03:10between fulcrum and effort so this much is its effort arm load arm is the
03:17distance between the load and the fulcrum so this much is its load arm so
03:23you can clearly see that the load arm is bigger than the effort arm so according
03:28to rule it will not give any mechanical advantage rather it will be more
03:35difficult to lift the load here so what we learned we learned the effort arm
03:42should be longer for getting the work done easily
03:48here we have a pair of scissors scissors to work on the principle of liver
03:57this is its effort this is fulcrum and this is the load area here we place the
04:05load the nearer the load the more easily it will be cut as a load arm would be
04:13smaller in that case so if you want to cut a cardboard with scissors placing it
04:20here will be difficult but if you place it near to the fulcrum the cardboard
04:26will be cut more easily as the effort arm would be longer and load arm would
04:32be shorter here we have pliers in case of pliers the effort arm is much longer
04:39than the load arm that's why pliers are very efficient to do very heavy tasks now
04:49let's learn about class 2 levers where the load is in the center here the effort
04:57arm is a distance between the effort and the fulcrum and the load arm distance
05:03between the load and the fulcrum so in every case of class 2 lever the effort
05:10arm is much longer than the load arm so class 2 levers are mostly used for
05:18heavyweight activities examples of class 2 levers include a wheelbarrow lemon
05:26squeezer bottle opener nutcracker all have load in the center and so all of
05:36them have effort arm much bigger than the load arm now let's learn about class
05:453 lever where effort is in the center effort arm is a distance between the
05:54effort and the fulcrum and load arm is a distance between the load and the
05:59fulcrum as effort is in the center so here in every case effort arm is going
06:07to be smaller than the load arm therefore larger effort is required to
06:15do a very small work this type of lever is used to do very light jobs like
06:22tweezers effort arm is much smaller than the load arm here here are more examples
06:32of class 3 levers and in all the cases effort being in the center the effort
06:40arm is much smaller than the load arm so kids today we learned about the effort
06:47arm and the load arms of different types of levers now you may go ahead and take
06:54a quiz to learn more bye-bye