Which best describes the difference between speed and velocity?
a) velocity is instantaneous.
b) speed is a vector quantity.
c) speed includes rate of change and direction.
d) velocity includes rate of change and direction.

this allows people to make the best decision or pursue the best option. when alternatives are weighed using their advantages and disadvantages, the option whose disadvantages outweigh the advantages (based on a qualitative or quantitative analysis) are shunned while those whose advantages outweigh their disadvantages are pursued.  

grav force prop 1/r squared 2r all squared is 4rsquared 1/4rsquared quartered