It has been covered seversl times. Rather than searching I will repeat the gist here. Stroj is the default neutral word. Mašina is a colloquial word that is also (even more colloquially) used to denote a train locomotive (train engine) or some road vehicles (esp. motorcycles).
Wat kind of exercise? You are commentig Czech to English.
Please make a screenshot next time.
Is there any distinction in Czech between the moral quality of goodness (She is a good person) and quality of construction or usefulness?
Distinction in which sense?
Dobrý is pretty much equivalent to good. You can have a good king, good food, good will, which are dobrý král, dobré jídlo, dobrá vůle.
I need help clarifying the difference between "Ten, Ta, To" and "Ty, Ti, Ta" because even my wife (who is Czech) is not able to describe the difference... For instance, for this phrase I wrote "These machines..." But I got corrected that it should be "Those machines..." But my wife says that "Ty" can be used to say "these" also (as for things that are close to the person who is speaking)