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00:00hi kids today we will learn or about mechanical advantage and how to find
00:08mechanical advantage in the case of a lever so let's start kids mechanical
00:17advantage is the measurement of how much a simple machine multiplies a force the
00:25bigger the mechanical advantage the lesser force you need let's learn it
00:31with examples we know lever has an effort arm and a load arm and the bigger
00:40the effort arm the bigger the mechanical advantage we can also calculate the
00:47mechanical advantage and that is by dividing the length of effort arm by
00:55length of the load arm let's learn it with examples this is the load arm of
01:01this lever that is distance from the load to the fulcrum and this is effort
01:08arm that is distance from effort to fulcrum length of the effort arm is 40
01:14centimeters and length of the load arm is 10 centimeters and 40 divided by 10
01:22we get 4 so mechanical advantage of this lever is 4 that is it will multiply the
01:31applied force by 4 if you apply 10 kg force it will make it 40 kg force in
01:40other words in order to lift a weight of 40 kg you need to apply a force of 10
01:47kg here is another example the length of the effort side is 60 centimeters here
01:58and the length of the load side is 20 centimeters now how can we find the
02:05mechanical advantage here and the mechanical advantage is length of effort
02:13arm divided by the length of load arm so it will be 60 divided by 20 that is 3 so
02:23the mechanical advantage in this case is 3 now let's take another example here
02:32the length of the effort side is 9 meters and the length of the load side
02:37is 3 meters so mechanical advantage will be 9 divided by 3 that is 3 let's find it
02:49the other way in case of this lever here we are given that the mechanical
02:55advantage of this lever is 3 and we have to find out how much force in kg is
03:02required to lift a weight of 12 kg we know the mechanical advantage of a
03:09lever is the length of effort arm divided by the length of the load arm
03:14and also mechanical advantage multiplied by the force applied in kgs equals the
03:22weight lifted up in kgs so here 3 multiplied by force applied in kgs
03:31equals 12 kgs so force applied in kgs is 12 divided by 3 that is 4 so we need 4
03:41kg force to be applied to lift a weight of 12 kg here here are some more
03:48examples here the effort arm is smaller than the load arm so it's difficult to
03:56lift the load let's calculate its ma its effort arm is 10 centimeters and the load
04:04arm is 50 centimeters so mechanical advantage is 1 by 5 that is it will
04:12multiply the force applied 1 by 5 if the 50 kg force will be applied 50
04:19multiplied by 1 by 5 is 10 kg so only 10 kg force will be forwarded that is it
04:28will even reduce the effort applied remember the effort arm should be longer
04:36for getting work done more easily here we have a scissor in figure a the length
04:45of effort arm is 20 centimeters and load arm is also of 20 centimeters so
04:51mechanical advantage is 1 in figure B length of effort arm is 20 and load arm
04:59is 5 centimeters so mechanical advantage will be 20 divided by 5 equals to 4 and
05:08the higher the mechanical advantage the lesser the force required so if you
05:15place the cardboard near to the fulcrum the more easily it will be cut another
05:22example is of pliers here the effort arm is 20 centimeters whereas the load
05:31arm is much much smaller which is 2 centimeters so ma or mechanical
05:39advantage will be 20 divided by 2 that is 10 so ma is 10 which is quite big
05:48that is applied force will be multiplied by 10 and this is a reason pliers are
05:57able to do tough jobs here is another example this is a class 2 lever here the
06:09effort arm is much bigger effort arm is 30 centimeters and then the load arm 10
06:17centimeters mechanical advantage is 3 and here is a class 3 lever where effort
06:27is in the center effort arm is always much smaller than the load arm and
06:34mechanical advantage is always less than 1 less than 1 means it does not multiply
06:43the effort applied but must be giving some other advantage we will learn about
06:50it in higher grades here we have a tweezer here effort 5 centimeters and
06:59load arm is 10 centimeters mechanical advantage is 5 by 10 that which equals
07:082.5 that is even less than 1 so third-class levers do not give mechanical advantage
07:18examples of third-class levers include a fork a stapler and a tweezer so kids
07:29today we learn a lot about the mechanical advantage of various types of levers now
07:37you may go ahead and take a quiz to learn more bye-bye