### Concept Items

#### 3.1 Acceleration

How can you use the definition of acceleration to explain the units in which acceleration is measured?

- Acceleration is the rate of change of velocity. Therefore, its unit is m/s
^{2}. - Acceleration is the rate of change of displacement. Therefore, its unit is m/s.
- Acceleration is the rate of change of velocity. Therefore, its unit is m
^{2}/s. - Acceleration is the rate of change of displacement. Therefore, its unit is m
^{2}/s.

- \text{m}^2\text{/s}
- \text{cm}^2\text{/s}
- \text{m/s}^2
- \text{cm/s}^2

- The car is accelerating because the magnitude as well as the direction of velocity is changing.
- The car is accelerating because the magnitude of velocity is changing.
- The car is accelerating because the direction of velocity is changing.
- The car is accelerating because neither the magnitude nor the direction of velocity is changing.

#### 3.2 Representing Acceleration with Equations and Graphs

A student calculated the final velocity of a train that decelerated from 30.5 m/s and got an answer of âˆ’43.34 m/s. Which of the following might indicate that he made a mistake in his calculation?

- The sign of the final velocity is wrong.
- The magnitude of the answer is too small.
- There are too few significant digits in the answer.
- The units in the initial velocity are incorrect.

Create your own kinematics problem. Then, create a flow chart showing the steps someone would need to take to solve the problem.

- Acceleration
- Distance
- Displacement
- Force

- v = v_0 + at
- v = v_0 - at
- v^2 = {v_0}^2 + at
- v^2 = {v_0}^2 - at