Answer:
Below
Step-by-step explanation:
AVERAGE speed of the truck is ( 26.7 + 6.7) /2 = 16.7 m/s
the time required at this avg speed to cover 800 m is
800 m / 16.7 m/s = 47.9 s
acceleration is change in velocity / change in time
( 6.7 - 26.7) / 47.9 = - .4175 m/s^2
Now: vf = vo + at
0 = 6.7 + (-.4175)t shows t = 16 more seconds to stop