PHYS 1420 Lecture Notes - Lecture 21: Kinetic Energy, Rotational Energy
Document Summary
Rational kinetic energy: something spinning may not have the location of its centre of mass moving. Rational motion not have any translational kinetic energy. It would have some motional energy, since it takes work to spin an object. Imagine only a small section of the wheel. It has some mass, and it is moving with some velocity. That piece has some kinetic energy: the kinetic energy of a small piece is (cid:2778)(cid:2779)(cid:2195)(cid:2779) This term is technically called the moment of inertia. Conservation of energy: this new type of energy should be added to our conservation of energy equation, (cid:3045)(cid:3042)(cid:3047)(cid:3047)(cid:3045)++(cid:3046)=(cid:3045)(cid:3042)(cid:3047)(cid:3047)(cid:3045)++(cid:3046) If a (cid:396)otati(cid:374)g o(cid:271)je(cid:272)t (cid:396)olls dow(cid:374) a hill without slippi(cid:374)g, the(cid:374) the (cid:396)elatio(cid:374)ship (cid:271)etwee(cid:374) it"s angular speed and translational speed is, as usual, If the(cid:396)e is so(cid:373)e slippi(cid:374)g, this e(cid:395)uatio(cid:374) does(cid:374)"t hold.