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LearningTranscript
00:00hi kids today we will learn what are gears so let's start kids gears are
00:10wheels with teeth gears can be of any size very small to very big gears can be
00:20made up of plastic or metal and remember gears always works in pairs gears always
00:31have teeth on them and teeth of one gear interlock with the teeth of the other
00:37gear so they are called meshed with each other and many gears can be joined with
00:44each other and when more than two gears are joined together we call it a gear
00:51train gears turn on the axle which in turn turns the wheel of the object to be
01:00moved so gears transfer forces and motion from one object to another and
01:09our work easier and faster gears can also change the speed and direction of
01:17the moving object driver driver is the first gear that starts the movement in a
01:26gear train gear wheels are mounted on axles and an axle is connected to some
01:37power source like it can be pedals in a bicycle that turns the axle connected to
01:44gears axle can be connected to some motor that runs the axle attached to the first
01:52gear or the driver gear and then driver gear turns the next mesh gear which can
02:00be attached to some other axle which is required to be moved gears can change the
02:08speed as well as the force of a machine let's see how when two gears of the same
02:17size mashup each gear turns at the same speed and there is no increase or
02:24decrease in speed and force but when a larger gear turns up a smaller gear the
02:33smaller gear turns up faster but with lesser force as a larger gear has more
02:43teeth and when it turns a smaller gear the smaller gear has to turn around much
02:51faster but with lesser force for example if a gear with 40 teeth turns up a gear with 20 teeth
03:01the gear with 20 teeth will move with twice the speed to move along with the 40 teeth gear but
03:09its force will be lesser than that of a bigger gear and this is what we call as gear up to
03:17increase speed example in the case of a bicycle with gears let's see what happens the paddles
03:31are attached to the driver gear and through paddles we crank the driver gear which in turn
03:40turns up the gears in the rear wheel and there are multiple gears in the rear wheel for various
03:47speeds like speeding up and speeding down let's see how does it happen when the driver gear
03:56cranks up a much smaller gear it runs faster and so is your cycle that is we gear up and when the
04:08driver gear using your pedals drives a larger gear in the rear wheel it moves slower and so
04:19is your cycle and this is what we call as gearing down that is the driver gear drives a larger gear
04:29it is gearing down and when the driver gear turns a smaller gear it is called gearing up so let's
04:39revise it all in our cycle the driver gear is attached with the pedals and using the pedals
04:46we drive the driver gear and when the driver gear turns up a smaller gear the cycle runs faster and
04:54it is known as gearing up and when the driver gear turns a larger gear the cycle runs slower
05:02and we call it as gearing down for example if a gear with 20 teeth turns up a gear with 40 teeth
05:12the gear with the 40 teeth will move with half the speed to move along with the 20 teeth gear
05:20and this is what we call as gearing down and gearing down decreases the speed remember gearing
05:34up gives the gear more speed but lesser force and gearing down gives the gear less speed but more
05:44force this is why when you start a car or any bike you have to start the engine from still so
05:54you need more force so lowest gear is used and when you just need speed the higher gear is used
06:04one more example if you want to ride up a hill you will need more force but less speed so you
06:14will drive a cycle on a lowest gear so that it has more force to climb up the hill gears can change
06:23the direction of movement too there are different types of gears and each gear is for different
06:33purposes gears differ from each other in the way teeth are arranged the types of teeth the way
06:42axles are put together and also the angles at which the teeth meet we will learn about each
06:50gear in our next assignment now you may go ahead and take a quiz to learn more bye