Answer:
The acceleration of the truck is, a = - 0.2 m/s²
Step-by-step explanation:
Given data,
The initial velocity of the truck, u = 14 m/s
The final velocity of the truck, v = 10 m/s
The time taken by the truck to reduce its velocity, t = 20 s
Using the first equations of motion,
v = u + at

Substituting the given values,

a = - 0.2 m/s²
The negative sign in the acceleration indicates that the truck is decelerating.
Hence, the acceleration of the truck is, a = - 0.2 m/s²