If you travel 30 miles somewhere and then come home again your distance is 60 miles. Your displacement is 0 because it is the ending position minus the beginning position, which are the same place (home). In other words, displacement is a vector and distance is a scalar.
I'd say a weekly news magazine.
Answer:
A thermos bottle works well because:
A) Its glass walls are thin
Newtons first law of motion is also known as the law of inertia