1. Rotational Kinematics Intro D Taylor © 2013

2. Non-Basic Stuff Inertia: – Mass, m, is measure of it regularly. Inertia is the property that resists a change in motion. I So, ROTATIONAL Inertia, I, is the property of an object that resists a change in its rotational state.

3. Non-Basic Stuff Rotasional Inertia: – Mathematical Definition :

4. Non-Basic Stuff Inertia: – SHAPE MATTERS !

6. Non-Basic Stuff Solid Disc

7. Non-Basic Stuff Hollow Disc

8. Non-Basic Stuff Solid Sphere

9. Non-Basic Stuff Bar at center

10. Non-Basic Stuff Bar at end

11. Non-Basic Stuff Torque : Rotational ‘ F ’

13. Figure 10.17 A large grindstone is given a spin by a person grasping its outer edge.

15. Rotational KE

18. Roll SOLID Disc Down Ramp?

20. Roll HOLLOW Disc Down Ramp?

22. Roll SOLID BALL Down Ramp?

23. L Finally; Angular Momentum (L) L L MUST be conserved!

24. Figure 10.24 The Solar System coalesced from a cloud of gas and dust that was originally rotating. The orbital motions and spins of the planets are in the same direction as the original spin and conserve the angular momentum of the parent cloud.

25. Figure 10.28 Figure (a) shows a disk is rotating counterclockwise when viewed from above. Figure (b) shows the right-hand rule. The direction of angular velocity ω size andangular momentum L are defined to be the direction in which the thumb of your right hand points when you curl your fingers in the direction of the disk’s rotation as shown.

26. Figure 10.29 In figure (a), the torque is perpendicular to the plane formed by r and F and is the direction your right thumb would point to if you curled your fingers in the direction of F. Figure (b) shows that the direction of the torque is the same as that of the angular momentum it produces.

27. Figure 10.36 The image shows a view down the barrel of a cannon, emphasizing its rifling. Rifling in the barrel of a canon causes the projectile to spin just as is the case for rifles (hence the name for the grooves in the barrel). (credit: Elsie esq., Flickr)

28. Satellite Orbit… vAvA vBvB

29. Spinning Skater?

30. Why? Hoberman!

32. Rotational Dynamics via Hollywood?

35. HA

36. Core #’s Inner Radius = 1200 km Outer Radius = 3470 km T both = 24 hrs Mass inner = 0.10 M earth Mass outer = 0.31M earth – Find Ke rot of core!

37. 500,000,000,000,000,000,000,000,000,000,000 J 500 Nonillion

38. 5x10 32 J 5x10 32 J Analogies? About the amount of energy the entire Sun emits in 100 seconds. That's a whole lot of energy. five trillion one megaton bombs If it doesn't sound like much, let's convert it to megatons: it's the equivalent energy of five trillion one megaton bombs 5,000,000,000,000 MILLION TONS TNT! going off at once. That is comfortably more than the entire arsenal of the planet. 500 million times – In fact, it's about 500 million times the explosive energy of every single nuclear weapon* on the Earth. *That we know of…