### Critical Thinking Items

#### 5.1 Vector Addition and Subtraction: Graphical Methods

True or False—A person is following a set of directions. He has to walk 2 km east and then 1 km north. He takes a wrong turn and walks in the opposite direction for the second leg of the trip. The magnitude of his total displacement will be the same as it would have been had he followed directions correctly.

- True
- False

#### 5.3 Projectile Motion

An object is launched into the air. If the y-component of its acceleration is 9.8 m/s^{2}, which direction is defined as positive?

- Vertically upward in the coordinate system
- Vertically downward in the coordinate system
- Horizontally to the right side of the coordinate system
- Horizontally to the left side of the coordinate system

#### 5.5 Simple Harmonic Motion

Two springs are attached to two hooks. Spring A has a greater force constant than spring B. Equal weights are suspended from both. Which of the following statements is true?

- Spring A will have more extension than spring B.
- Spring B will have more extension than spring A.
- Both springs will have equal extension.
- Both springs are equally stiff.