A parachutist relies on air resistance (mainly on her parachute) to decrease her downward velocity. She and her parachute have a mass of m and air resistance exerts a total upward force of f on her and her parachute.

The correct answer is b, social stratification is needed for a society to exist. marxist theory regarding social stratification is that due to the differing economic capacities among people in society, a natural separation occurs between those that own the means of production and those that sell their labour in the production chain. 

Take a break, read a book, take a nap, self-care really

Establish a study routine & set up a distraction-free study environment! (All answers apply but Sofia should focus on those two.)