Answer:
[tex]0.28 m/s^2[/tex]
Explanation:
Acceleration is given by
[tex]a=\frac{v-u}{t}[/tex]
where
u is the initial velocity
v is the final velocity
t is the time interval
In this problem:
[tex]u = 10 km/h \cdot \frac{1000 m/km}{3600 s/h}=2.78 m/s[/tex] is the initial velocity
[tex]v = 8 km/h \cdot \frac{1000 m/km}{3600 s/h}= 2.22 m/s[/tex] is the final velocity
t = 2 s is the time
Substituting, we find the acceleration:
[tex]a=\frac{2.78-2.22}{2}=0.28 m/s^2[/tex]