Answer:
[tex]V_{average}=70m/s[/tex]
Explanation:
The average velocity is the distance traveled by an object divided by the time used to travel. Here you don't have the distance or the time, but the acceleration is constant so you can use this formula:
[tex]V_{average}=\frac{v_i+v_f}{2}[/tex]
Where [tex]v_i[/tex] is the initial velocity and [tex]v_f[/tex] is the final velocity:
[tex]V_{average}=\frac{v_i+v_f}{2}\\V_{average}=\frac{0+140}{2}\\V_{average}=\frac{140}{2}\\V_{average}=70m/s[/tex]
