A car initially going 30ft/sec brakes at a constant rate (constant negative acceleration) coming to a stop in 4 seconds. How far did the car travel?

Answer 1

simple minded way: average velocity was 15ft/sec, for 4 seconds, 60ft

Nerd way:
distance= Vi*t- 1/2 a t^2

where a= changevelociy/time= 30/4

distance= 30*4-1/2 30/4 * 4^2 and that works out to ...duh...60 ft.