Acar traveling at 22 m/s starts to decelerate steadily. it comes to a complete stop in 5 seconds. what is its acceleration?

For uniform acceleration (or deceleration in this case), you use the formula:

Vf = Vi + at

Vi = 22 m/s
Vf = 0 (coming to a stop)
t = 5 sec

Plugging everything into the formula gives you:

0 = 22 + 5a
-22 = 5a
a = -22/5 or -4.4 m/s^2

Hope this helps!

Less force and energy was applied