Aspeed versus time graph is shown: a speed versus time graph is shown with y-axis labeled position in centimeters per second up to 5 and x-axis labeled time in seconds up to 8. a straight line connects the points 0, 0 and 4, 4. a horizontal line connects points 4, 4 and 8, 4. which statement accurately describes the motion of the object in the graph above? it is moving from 0 s to 4 s at a constant speed of 2 cm/s. it is at rest for 4 seconds from 4 s to 8 s and then speeds up. it is moving from 4 s to 8 s at constant speed of 4 cm/s. it is speeding up from 0 s to 4 s then it is at rest.

It is moving from 4s to 8s at a constant speed of 4 cm/s

Explanation:

The graph would show a line with a positive gradient, this would mean that the speed would increase as more time passed. This means that it was accelerating from 0s to 4s. Thus this disproves the first option.

For the second option, we know that this is a speed time graph, so a horizontal line would symbolise constant speed. Therefore, it wouldn't be at rest and also makes the third option correct.

For the last option, the first part is correct in saying that it is 'speeding up' as we do see the speed increase due to the positive gradient. However, from the previous option (which is correct) we know that it isn't at rest and is moving at constant speed. Therefore, the last one is wrong.

And thus, the only correct option is option 3.

b. a lightning bug, plug of grass, and a worm