A certain sporty car claims that it does "zero to sixty (mi/h) in 6.2 s".

How farhas it traveled by then?

First, we need to find the

accelertion.Life will be somewhat simpler if we change the velocity to SI units of km/h or, better yet, to m/s

v = 60

^{mi}/_{h}[^{1.61 km}/_{mi}] [^{h}/_{60 min}] [^{min}/_{60 s}] [^{1 000 m}/_{km}]v = 26.8 m/s

(Hmmmm, . . . that

looksfamiliar. We've seen it before but it's not worth memorizing).a = (v - v

_{i}) ta = (26.8 m/s) / (6.2 s)

a = 4.32 m/s

^{2}Now,

how fardoes it travel in thattime?x = x

_{i}+ v_{i}t + (^{1}/_{2}) a t^{2}x = 0 + 0 + (

^{1}/_{2}) (4.32 m/s^{2})(6.2 s)^{2}Do a quick dimensional analysis and notice that the units are

consistent.x = 83.0 m

(c) 2000, Doug Davis; all rights reserved.