# I Point of Reference for Conservation of Angular Momentum

1. Mar 8, 2017

### angelatan

When analyzing the conservation of angular momentum of a particular system, should we use the same p.o.r. before and after or can we use different p.o.r.'s? As far as I know, we should always use the same reference, but sometimes I see several solutions that use different references in my textbook.

Thank you for your help, and pardon my awkward English

2. Mar 9, 2017

### Orodruin

Staff Emeritus
You need to use the same point of reference if the total linear momentum is non-zero. In the same fashion, angular momentum can be preserved with respect to one reference point while not being conserved with respect to another if the total force is non-zero.

If the total linear momentum is zero, the angular momentum is independent of the reference point. If the total force is zero, the torque is independent of the reference point.

3. Mar 11, 2017

### Quantum Aravinth

Can you please explain it further?

4. Mar 11, 2017

### Orodruin

Staff Emeritus
Not unless you point out what parts you have problems with.

5. Mar 23, 2017

### Quantum Aravinth

I was entirely confused,
Can you please explain it with a simple system? Be it any system