the driver of the truck going 50 mph applies the brakes giving the truck a deceleration of 4.5 m/s^2 how long will it take the truck to come to a complete stop what distance will it cover
50mi/hr = 22.35m/s
22.35m/s / 4.5m/s^2 = 4.97s
Now just plug in for distance:
s = vt - 1/2 at^2