<PRE><B>Question 1003146</B>


As a truck brakes to a stop from 55mph,it covers the length of a football field (300ft) it takes the trucks 15 seconds to come to a stop. How many feet does the truck brake per second?

As a truck brakes to a stop from 55mph,it covers the length of a football field (300ft)=s


 it takes the trucks 15 seconds to come to a stop.=t

 55mph = 80.67 ft/s

s= ut+1/2 at^2

300 = 80.67*15 +1/2 a (15)^2

300 - 80.67*15 = 1/2 a *225

-910.05 = 1/2 a * 225

2*-910.05/225 = a

a=-8.09

deceleration 
</PRE>