It depends on what illness and what country you are in but Mayo Clinic and Johns Hopkins are good sources.
Gravity, and Normal. Check the comments for why Applied isn't one.
Down stream it would be going 20 mph and up stream 10 mph
Speed has only magnitude and no direction.
Answer:

Explanation:
The impulse or average force in classical mechanics is the variation in the linear momentum that a physical object experiences in a closed system. It is defined by the following equation:

Where:





Asumming v1=0 and t1=0:
