Answer:
D) Acceleration is positive and increasing.
Explanation:
Acceleration is defined as the rate of change of velocity per unit time; in formulas:
\(a=\frac{\Delta v}{\Delta t}\)
where \(\Delta v\) is the variation of velocity and \(\Delta t\) is the variation in time.
The graph shows the velocity vs the time of a moving object. We can see that \(\Delta v\) is the increment on the y-axis, while \(\Delta t\) is the increment on the x axis: therefore, the ratio \(\frac{\Delta v}{\Delta t}\) is the slope of the curve. In fact, in a velocity-time graph, the slope of the curve corresponds to the acceleration of the object.
In this particular graph, we see that the slope of the curve continues to increase: therefore, the acceleration is positive (because the slope is positive, since the velocity is increasing) and increasing (because the slope is increasing).
