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Explore the principles of rigid body dynamics, translation, rotation, moment of force, and torque through engaging ICT presentations. Suitable for high school students with CLIL physics lessons in English.
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Škola: Gymnázium, Brno, Slovanské náměstí 7 Šablona: III/2 – Inovace a zkvalitnění výuky prostřednictvím ICT Název projektu: Inovace výuky na GSN prostřednictvím ICT Číslo projektu: CZ.1.07/1.5.00/34.0940 Autor: RNDr. Bc. Miroslav Hruška Tematická oblast: Gravitational field and motion of bodies (gravitační pole a pohyb těles) Název DUMu: Rigid body and its motion Kód: VY_32_INOVACE_FY.4.07 Datum: 23. 2. 2014 Cílová skupina: Žáci středních škol s CLIL výukou fyziky v angličtině Klíčová slova: Rigid body, solid body, deformation, translation, rotation, moment of a force, torque, turning effect Anotace: Prezentace zavádí model tuhého tělesa a definuje moment síly vzhledem k ose otáčení.
Gravitational field and motion of bodies 7. Rigid body and its motion
Rigid body (tuhé těleso) • Rigid body is a model of a solid body in which deformation is neglected • Why do we use models? • Find a solid body which cannot be considered as rigid
Translation • At translation all points of the body have identical trajectories • All points have equal velocities • Translation can be rectilinearor curvilinear!
Rotation • At rotation all points of the body revolve around the same axis • All points have equal angular speeds • We are going to study rotation around a fixed(pevné) axis
Moment of a force (torque) O d • Moment of a force about an axis of rotation(moment síly vzhledem k ose otáčení) is the product of the force and the perpendicular distance from theline of action(vektorové přímky)of the force to the axis of rotation • http://www.youtube.com/watch?v=aW8RrEmRCo4#aid=P-A0hgt3Xmc cca 2 min
Torque • When a force tends to produce rotation, torque describes the turning effect of the force • The sense(smysl)of the turning effect about the axis can be clockwise or anticlockwise (counterclockwise) • Therefore moment of a force is a vector
Torque as a vector d= moment arm of the force (rameno síly) • The vectorpoints according to theright-hand (-thumb) rule…
Moment of several forces • When several torques act on a body, the net torque or resultant torque is the sum of the individual torques • When the net torque is a zero vector, the turning effects of the forces are cancelled
Fill in the gaps • Rigid body is a ……… of a solid body in which deformation is …………… • Moment of a force about an ……… of rotation is the ………… of the force and the ………………… distance from theline of ……… of the force to the ……… of rotation • When a force tends to produce rotation, ……… describes the turning ………… of the force
Fill in the gaps - solution • Rigid body is a model of a solid body in which deformation is neglected • Moment of a force about an axis of rotation is the product of the force and the perpendicular distance from theline of actionof the force to the axis of rotation • When a force tends to produce rotation, torque describes the turning effect of the force
That is all for now Thank you for your attention
Materiál je určen pro bezplatné používání pro potřeby výuky a vzdělávání na všech typech škol a školských zařízeních. Jakékoliv další využití podléhá autorskému zákonu. Zdroje: • Bednařík, M., Široká, M. Fyzika pro gymnázia, Mechanika. Dotisk 3. vyd. Praha: Prometheus, 2004. 288 s. ISBN 80-7196-176-0 • Hornby, A. S. Oxford Advanced Learner’s Dictionary of Current English. 5. vyd. Oxford: Oxford University Press, 1995. 1428 s. ISBN 0-19-431423-5
