They want you to find the average velocity of a car that goes 160 miles north and 120 miles east. they do D = $$\sqrt{(160^2 + 120^2 }$$ = 200 miles. Then they do tan^-1 120/160 = 36.87, then 90 - 36.87 = 53.13. WHY do they choose the "90"? because they have chosen different numbers in different problems...

Question

amistre64 · Answer

velocity is a scalar, not a vector; so directions mean nothing

amistre64 · Answer

spose we have an interval from [a,b] such that we know the speed at a; f(a).  and we know the speed at b; f(b)

the average velocity is then just:

f(b)-f(a)
-------
  b-a

amistre64 · Answer

the 90 here would refer to the right angle formed by turning; the other part is the angle of the tangent of the 2 distances; but i got no idea how that relates to avg. velocity ...

anonymous · Answer

but in other similar problems, they use numbers like 180, and sometimes that add instead of subtracting...