How can you tell this isn't "Are those new machines?" It's probably really obvious...
I think the adjective should come before the noun in that case. Let's wait for a native to answer to that.
Since word order doesn't matter apparently, couldn't it also be "Jsou to mašiny nové?"
When an adjective works as a grammatical modifier in the sentence, it comes before the name.
They would of course understand your version too, but it sounds weird. It would be acceptable in a poem though ;-).
Thank you for clarifying. This discussion section is very helpful because the lessons won't tell you "No one says it like that" or "it's technically right, but people would look at you crazy."
Mašina and stroj are synonyms. Stroj is neutral, mašina is a bit outdated and a bit expresive.
I think I also read that mašina is used to specifically refer to train locomotives, rather than a generic "machine"?