Re: Angular momentum


Fallingeagle wrote:
Can someone explain Why the total angular momentum of a system with a
pully, and two masses joined by a massless string overt the pully
equals the angular momentum of the pully + the angular momentum of the
two masses?

why: L(sys) = L(pully) + L(masses)

I omega + m1 * v * r + m2 * v * r

This is what I do not understand:

the spin (AM) of the pully is caused by the the two masses, why is the
total spin not just the spin of the pully?

also: what is spin (angular momentum)....really??

For a point particle, angular momentum is defined as the cross product
of it's radial position vector r and it's linear momentum. i.e L = r x
p.

For a system of particles, total angular momentum = sum(k = 1 to n)
[L_k]
So for your pully system, Ls = Lp + Lm1 + Lm2

Thing to note is that angular momentum of a system depends on choice of
origin of coordinate system, and that a particle moving in a straight
line has a non-zero angular momentum.

Hope this helps.

.