Force and Motion Unit Test

Question

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Question
Use the graph showing the motion of a person over time to answer the question.

The vertical axis is labeled, position from home (km), and ranges from a 0 km to 14 km. The horizontal axis is labeled, time (minutes) and labeled from 0 minutes to 50 minutes. The graph shows a line that starts from the origin and slopes upward to 12 km at 10 minutes. The line remains at 12 km from 10 minutes to 30 minutes. The line slopes downward from 12 km to 0 km from 30 minutes to 45 minutes.

Which statement correctly compares his motion during the first 10 minutes to his motion during the last 10 minutes?

(1 point)
Responses

He is going faster and in a different direction during the first 10 minutes than in the last 10 minutes.
He is going faster and in a different direction during the first 10 minutes than in the last 10 minutes.

His acceleration increases during the first 10 minutes and decreases during the last 10 minutes.
His acceleration increases during the first 10 minutes and decreases during the last 10 minutes.

He is speeding up during the first 10 minutes and slowing down during the last 10 minutes.
He is speeding up during the first 10 minutes and slowing down during the last 10 minutes.

He is going slower and in a different direction during the first 10 minutes than in the last 10 minutes.
He is going slower and in a different direction during the first 10 minutes than in the last 10 minutes.

Answer 1

To analyze the motion based on the provided graph description:

• During the first 10 minutes, the person moves from the origin (0 km) to 12 km, which indicates a consistent increase in position over time. This implies that the person is moving at a steady speed.

• From 30 to 45 minutes, the person's position decreases from 12 km back to 0 km, which indicates a return toward the starting point. This implies they are moving in the opposite direction and likely slowing down, as the slope of the line going down would be less steep compared to the slope going up (unless specified otherwise).

Now, let's assess the response options in the context of this analysis:

1. "He is going faster and in a different direction during the first 10 minutes than in the last 10 minutes." - This is true because the speed is higher during the first 10 minutes (moving away from home) and the direction changes in the last 10 minutes (returning home).

2. "His acceleration increases during the first 10 minutes and decreases during the last 10 minutes." - This is not accurate, as the motion appears to be at a constant speed in the first segment (constant position change) and does not indicate an acceleration.

3. "He is speeding up during the first 10 minutes and slowing down during the last 10 minutes." - This is inaccurate, as he is moving at a steady pace during the first 10 minutes and then slowing down afterward.

4. "He is going slower and in a different direction during the first 10 minutes than in the last 10 minutes." - This is incorrect because he is not going slower during the first 10 minutes.

The best option is the first one:

"He is going faster and in a different direction during the first 10 minutes than in the last 10 minutes."