Solved Motion Graphs & Kinematics Worksheet: 1. The graph | Chegg.com - Free Printable

Problem Analysis:

The given graph is a velocity vs. time graph for a fly that starts moving to the left. The velocity is plotted on the vertical axis (in meters per second, m/s), and time is plotted on the horizontal axis (in seconds, s). Positive velocities indicate motion to the right, while negative velocities indicate motion to the left.

We need to analyze the graph to answer the following questions:

1. Identify sections where the fly moves with constant velocity.
2. Identify sections where the fly moves right slowing down.
3. Identify sections where the fly moves left speeding up.
4. Determine when the fly is at rest.

Solution:

#### a. Identify section(s) where the fly moves with constant velocity.

- Constant velocity is represented by a horizontal line on a velocity-time graph because the velocity does not change over time.
- From the graph:
- Between 8 s and 10 s, the velocity is constant at approximately 10 m/s (positive, indicating motion to the right).
- Between 15 s and 20 s, the velocity is constant at approximately -5 m/s (negative, indicating motion to the left).

Thus, the sections where the fly moves with constant velocity are:
- 8 s to 10 s
- 15 s to 20 s

#### b. Identify section(s) where the fly moves right slowing down.

- Moving right means the velocity is positive.
- Slowing down means the velocity is decreasing (the slope of the velocity-time graph is negative).
- From the graph:
- Between 10 s and 15 s, the velocity is positive (indicating motion to the right) and decreasing (the slope is negative).

Thus, the section where the fly moves right slowing down is:
- 10 s to 15 s

#### c. Identify section(s) where the fly moves left speeding up.

- Moving left means the velocity is negative.
- Speeding up means the magnitude of the velocity is increasing (the slope of the velocity-time graph is negative for negative velocities).
- From the graph:
- Between 0 s and 2 s, the velocity is negative (indicating motion to the left) and becoming more negative (the slope is negative), which means the fly is speeding up to the left.

Thus, the section where the fly moves left speeding up is:
- 0 s to 2 s

#### d. When is the fly at rest?

- The fly is at rest when its velocity is zero.
- From the graph:
- At 2 s, the velocity crosses the zero line from negative to positive.
- At 8 s, the velocity crosses the zero line from positive to negative.

Thus, the fly is at rest at:
- 2 s
- 8 s

Final Answers:

\[
\boxed{
\begin{array}{l}
\text{a. } 8 \text{ s to } 10 \text{ s and } 15 \text{ s to } 20 \text{ s} \\
\text{b. } 10 \text{ s to } 15 \text{ s} \\
\text{c. } 0 \text{ s to } 2 \text{ s} \\
\text{d. } 2 \text{ s and } 8 \text{ s}
\end{array}
}
\]