Chapter 2  Reality Check

My mom got a new Corvette this summer.  I was out driving with my dad and wanted to see how much power this thing really had.  So when I was at a stop sign, I nearly floored it.  At the other side of the intersection I was doing about 35 mph.  Approximate the length of an intersection so you may approximate the acceleration of the car.  How many g’s of acceleration is this (1g = 9.8 m/s²)?

35 mph (.447 m/s / 1mph) = 15.6 m/s

Estimate the distance of an intersection to be about 45 ft or about 15 meters.

Calculate acceleration from the known info

x0 = 0 :  x = 15:  v0=0  : v=15.6   a= ?  : t = don't know

Use the equation:  v²=v₀²-2a(x-x₀)

                       (15.6)²= 2a(15)

                          a= 243/30=8.11 m/s

                                  a in g's = 8.11/9.8 = 0.82