Answer:
C) from 4.5 to 5.0 seconds
Explanation:
The graph shows the distance of the ball from the initial point (y-axis) against the time (x-axis).
In such graph, the speed of the ball corresponds to the slope of the curve, since it is equal to the ratio between the distance travelled (increment in the y-axis) and time taken (increment in the x-axis):
[tex]v=\frac{\Delta y}{\Delta x}=\frac{d}{t}[/tex]
Therefore, we can say that the object is moving when the slope of the curve is not zero: when the slope of the curve is zero, instead, the object is at rest.
From the graph, we observe that between t=4.5 s and t=5.0 s the slope of the curve is zero, because the curve is horizontal. This means that the speed is zero, so the object is not moving.
