مبدأ حفظ الطاقة و البندول

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مبدأ حفظ الطاقة و البندول

PHYSTUBE · ⏱ 3:38 · 30.7K مشاهدة · 9 years ago

النص الكامل للفيديو

have here pendulum have an object that weighs 15 kg and can lift it up one ler which have done now that means I've done work MGH is the work have done believe me have increased the potential energy of this object 15 * 10 is about 150 Jews if let it fall then that will be converted to kinetic energy if would let it swing from one meter height and you would be there and it would hit you you'd be dead 150 Jews is enough to kill you they use these devices they called rer ball they use them to demolish buildings you lift up very heavy object even heavier than this and then you let it go you swing it thereby converting gravitational potential energy into kinetic energy and that way you can demolish building you just let it hit and it breaks the building and that's the whole idea of wrecking so you are using then the conversion of gravitational potential energy to kinetic energy now am such strong believer of the conservation of mechanical energy that am willing to put my life on the line if release that Bob from certain height then that Bob can never come back to point where the height is any larger if release it from this height and it swings then when it reaches here it could not be higher there is conversion from gravitation potential energy to kinetic energy back to gravitational potential energy and it will come to stop here and when it swings back it should not be able to reach any higher provided that do not give this object an initial speed when stand here trust the conservation of mechanical energy for 100% may not trust myself I'm going to release this object and hope will be able to do it at zero speed so that when it comes back it may touch my chin but it may not Crush my chin want you to be extremely quiet because this is no joke if don't succeed in giving it zero speed then this will be my last lecture will close my eyes don't want to see this so please be very quiet almost didn't sleep all night 3 2 1 zero physics work and I'm still alive see you Wednesday