A speed 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.

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.

oeerivona oeerivona · Answer 2 · 2021-08-20T18:01:54+02:00

The aspect of a speed time graph having a horizontal line indicates constant speed

The statement that describes he objects motion is the option;

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

The reason for making the above selection is as follows:

The known parameters on the Speed versus Time graph are;

The label of the y-axis with 5 points = centimeters per second (speed units)

The label on the x-axis with 5 points = Seconds (Units of time)

Points on the graph are; (0, 0), (4, 4), and (8, 4)

Points (0, 0) and (4, 4) are connected with a straight line

Points (4, 4) and (8, 4) are connected with a horizonal line

Required information:

The statement that accurately describes the motion of the object in the graph

Strategy:

Evaluate the speed and time of the object at each point

Calculate the slope of the speed time between two points to find the acceleration of the object

Solution:

At point (0, 0), time = 0 s, the speed = 0 cm/s

At point (4, 4), time = 4 s, the speed = 4 cm/s

At point (8, 4), time = 8 s, the speed = 4 cm/s

Therefore, the speed of the object increases (it is speeding up) from 0 to 4 cm/s as it moves from 0 s to 4 s

The speed of the object from 4 s to 8 s is constant (remains at 4 cm/s)

Acceleration (to verify);

The acceleration between points (0, 0) and (4, 4), a₁ = (4 - 0)/(4 - 0) = 1

The acceleration between points (0, 0) and (4, 4), a₁ = 1 cm/s²

The acceleration between points (4, 4) and (8, 4), a₂ = (4 - 4)/(8 - 4) = 0

The acceleration between points (4, 4) and (8, 4), a₂ = 0, the object is moving at a constant speed between points (4, 4) and (8, 4), which is from 4 s to 8 s

Therefore, the statement that accurately describes the motion of the object in the graph is that; It is moving from 4 s to 8 s at constant speed of 4 cm/s

Learn more about speed time graphs here:

https://brainly.com/question/13969917