Can you bring me back some milk?

One is on the couch watching TV eating cookies. The other one got up and is headed for the kitchen.

Can I use "get" as an alternative to "bring back" in the above sentence?

Thanks again for your kind help.

Yes.
Would you get me some milk?

The speaker and the listener are together. The listener is leaving, going to a place where there is milk, but will be coming back. The speaker says
"Can you bring me back some milk?", meaning "When you come back, can you bring me back some milk?"
If the speaker says "Can you get me some milk?", that is more of a request by the speaker for the listener to go and get the milk.

Not necessarily. The listener may be out and phoning the speaker who may have replied to the question, 'Do you want me to get you anything from the shops?'

The sentence alone is too vague, more context is needed to establish for certain where the two parties are in relation to each other.

Would you please be so kind as to explain when or in which context I should use the two sentences above?

Thank you.

Is this a physics problem? We have a resident physick.

When indeed.

While search teams expect to find the sheep in the meadow and the cows in the corn within the hour, there's no word yet on little boy blue and little bo peep's whereabouts which one hunter described as "like trying to find a needle in a haystack".

Whenever someone is asking someone to bring them back some milk from wherever they're going. It could be anywhere, work, home, club or anywhere else really. The two individuals could be in the same room/building or talking on the phone/internet.

Paik

What is it that you don’t understand?

It is simply asking someone to do something. It is asking another person to do a task, stating the request as a question instead of a denand.

Request/Question:
Can you get me the hammer?
Will you hand me the hammer?

Demand or order:
Give me the hammer.
Get the hammer.