Answer:
B. Gravity and air resistance
Explanation:
Experimentation has proven that :
When the parachute opens, air resistance becomes much greater than gravity. The forces are no longer balanced and this changes the
speed
Creating new elements in order to study their properties is definitely pure research.
It has no earthly [known] application, since the elements don't even exist, whereas
for each of the other choices, you've stated the desired application as the reason
for the search.
Iron nails are attracted to the magnet
Height and depth..... for sure....
