1 / 6

100 likes | 660 Vues

Conservation of Angular Momentum, Change in Angular Momentum and, Angular Impulse. October. Conservation of Angular Momentum. L mom is a conserved quantity/remains constant in the absence of an external force (i.e. torque)

Télécharger la présentation
## Conservation of Angular Momentum, Change in Angular Momentum and, Angular Impulse

**An Image/Link below is provided (as is) to download presentation**
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.
Content is provided to you AS IS for your information and personal use only.
Download presentation by click this link.
While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

**Conservation of Angular Momentum, Change in Angular Momentum**and, Angular Impulse October**Conservation of Angular Momentum**• Lmom is a conserved quantity/remains constant in the absence of an external force (i.e. torque) • Since Lmom is a constant for an isolated system, and because the Lmom formula can be rearranged to give v = Lmom /(mr), the velocity v and the separation r are inversely correlated. • thus, conservation of angular momentum demands that a decrease in the separation r be accompanied by an increase in the velocity v, and vice versa. • We observed this during our Ironman demo: mrBIGvsmall = mrsmallvBIG Another example**Change in Angular Momentum**• How do we deal with a change in angular momentum (∆ Lmomor∆ Iω)? • The same way we did with a change in linear momentum • Recall, for linear momentum: Change in linear momentum = ∆P= m∆v • Same for change in angular momentum except symbols change: Change in Angular momentum = ∆Lmom= I ∆ ω where ∆ ω = ω2- ω1 • Let’s try Example 2 part “a” from pg.56**Angular Impulse**• Recall from linear impulse that J=F∆t which means that a linear impulse is the result of a force applied in a certain amount of time ex. Hydraulic spreader (HUGE jaw force applied to outer edges of car door for 1min results in HUGE IMPULSE to pry open door) • Angular Impulse is what causes objects to start or stop rotating • Like linear impulse it still happens in a certain amount of time EXCEPT, since rotation, the force required to start that rotation is called TORQUE • TORQUE is a force applied from a certain distance from the center of object such that; Torque(T) = Fxd where F(N or lb), d (m or ft), T (N.m or lb.ft)**Working with Angular Impulse**• Angular Impulse causes rotation when torque (F x d) is applied to an object in a certain period of time. • Screw begins to turn due to angular impulse applied from wrench Ang.Imp. = (Fxd)∆t where Ang.Imp. has units (N.m).s or (lb.ft).s • we could re-write equation as Ang.Imp.= T∆t • And of course don’t forget: Impulse (in this case angular impulse) is what causes change in momentum so: • Let’s try part “b” of Example 2 pg.56 T∆t = I∆ω**Classwork/Homework (whatever is not finished in class must**be finished for hmwk) • Read pg.44-50 • Complete Qd-g from Let’s Review units on pg.55 • Complete Student Exercises(#1-11) on pg.51. You must write out the full question for Q1-10 and use GFS for #11. • Answer Qs #4-6 on pg.57 of workbook

More Related