### Short Answer

### 3.1 Acceleration

True or Falseâ€”The vector for a negative acceleration points in the opposite direction when compared to the vector for a positive acceleration.

- True
- False

- â€“5 m/s
- â€“1 m/s
- 1 m/s
- 5 m/s

How is the vector arrow representing an acceleration of magnitude 3 m/s^{2} different from the vector arrow representing a negative acceleration of magnitude 3 m/s^{2}?

- They point in the same direction.
- They are perpendicular, forming a 90Â° angle between each other.
- They point in opposite directions.
- They are perpendicular, forming a 270Â° angle between each other.

How long does it take to accelerate from 8.0 m/s to 20.0 m/s at a rate of acceleration of 3.0 m/s^{2}?

- 0.25 s
- 4.0 s
- 9.33 s
- 36 s

### 3.2 Representing Acceleration with Equations and Graphs

If a plot of displacement versus time is linear, what can be said about the acceleration?

- Acceleration is 0.
- Acceleration is a non-zero constant.
- Acceleration is positive.
- Acceleration is negative.

True or False: â€”The image shows a velocity vs. time graph for a jet car. If you take the slope at any point on the graph, the jet carâ€™s acceleration will be 5.0 m/s^{2}.

- True
- False

When plotted on the blank plots, which answer choice would show the motion of an object that has uniformly accelerated from 2 m/s to 8 m/s in 3 s?

- The plot on the left shows a line from (0,2) to (3,8) while the plot on the right shows a line from (0,2) to (3,2).
- The plot on the left shows a line from (0,2) to (3,8) while the plot on the right shows a line from (0,3) to (3,3).
- The plot on the left shows a line from (0,8) to (3,2) while the plot on the right shows a line from (0,2) to (3,2).
- The plot on the left shows a line from (0,8) to (3,2) while the plot on the right shows a line from (0,3) to (3,3).

When is a plot of velocity versus time a straight line and when is it a curved line?

- It is a straight line when acceleration is changing and is a curved line when acceleration is constant.
- It is a straight line when acceleration is constant and is a curved line when acceleration is changing.
- It is a straight line when velocity is constant and is a curved line when velocity is changing.
- It is a straight line when velocity is changing and is a curved line when velocity is constant.