A car traveling at 42 ft/sec decelerates at a constant 7 feet per second squared. How many feet does the car travel before coming to a complete stop?

Answer 1

v = 42 - 7 t
when does v = 0?
t = 42/7

x = (1/2) a t^2
= (7/2)(42^2/49)
= 42^2/14
= 126 feet