Answer:
The last graph
Explanation:
Acceleration is defined as the rate of change in velocity per unit time:
[tex]a=\frac{\Delta v}{\Delta t}[/tex]
where [tex]\Delta v[/tex] is the change in velocity while [tex]\Delta t[/tex] is the change in time.
In a velocity-time graph, the acceleration also corresponds to the slope of the curve. Among all the graphs shown here, only the second one and the 4th one shows a velocity-time graph. Among these two, only the 4th graph shows a curve with positive slope: this means that the velocity is increasing, so the acceleration of the object is positive.
