Question

can someone explain the basics of "Conservation of Angular Momentum"? I don't need a thorough explanation, just something basic enough so I can go into class understanding the basics. PLEASEEE :)

Answer 1

Well.. the basic is just like conservation of linear momentum, which says,

if there is no net EXTERNAL force acting on a system, then its momentum is conserved
ergo\[\frac{dP_{system}}{dt}= 0\ \ \ if\ \ \ ({F_{net}})_{external}=0\]

similarly for a system of particles, the angular momentum of the system is conserved, if there is no net EXTERNAL TORQUE acting on the system

\[\frac{dL_{system}}{dt}= 0\ \ \ if\ \ \ ({\tau_{net}})_{external}=0\]

Answer 2

Okey dokey, and could you explain real quick where inertia ties into it? like where it changes?

Answer 3

well just like how momentum = mass * velocity
and mass is measure of inertia in linear motion

similarly Angular momentum = Moment of inertia * angular velocity

so take ice skater for example.
when ice skater starts out spinning, she starts with legs and arms wide apart (high moment of inertia), and then she retracts them decreasing her moment of inertia.. but but but but but, there is no TORQUE external acting on her.. which means, her angular momentum should stay constant

but but but hey.. her moment of inertia has decreased.. so to keep angular momentum constant, what should happen to angular velocity???

Answer 4

here is a video that i made to explain the concept :P

https://www.youtube.com/watch?v=J14NnWLaFWI

Answer 5

so she spins faster?

Answer 6

yup you got that right!

Answer 7

(which means higher angular velocity?)

Answer 8

yessa!

Answer 9

okay! thank you!

Answer 10

Is there anything else I should know that would help understand conservation of angular velocity? Like is there anything else that ties into it?

Answer 11

conservation of angular MOMENTUM, not velocity.. that is the basics.. !

Answer 12

okey dokey, do you by any chance know where I could find worksheets or practice problems? I have my final exam monday and I realllllyyyyy need to study

Answer 13

That depends on what level you are dealing with.. which grade is this?

Answer 14

general college physics?

Answer 15

u basically want on angular momentum conservation ?

Answer 16

mmm, yeah, but if it includes the other concepts that would work so I could cover/study the other topics too

Answer 17

From edx :D

Answer 18

thaaaaaaaank youuuuuuuu :)!!!

Answer 19

yea.. i have a coupla of problems.. ll upload one by one!

Answer 20

those are the kinds you want right?

Answer 21

yes!

Answer 22

ok.. a couple more coming up :D

Answer 23

okey dokey, thank you so much!!!!

Answer 24

No problem :)

Answer 25

ok once you finish them, if you need more. ..ll post more :P..

Answer 26

alrighty :) I'll let you know tomorrow, I'm going to go to sleep its past 3am here and I'm dead tired hahaha thanks again!

Answer 27

haha.. oki.. good night ..! ^_^