### Unit 2: Motion in a Straight Line

Our formal study of physics begins with kinematics, which is defined as the study of motion without considering its causes. The word "kinematics” comes from a Greek term meaning "motion.” In this unit, we will study motion without worrying about what forces cause or change it. Such considerations come in later units. In this unit, we will examine the simplest type of motion - namely, motion along a straight line, or one-dimensional motion.

**Completing this unit should take you approximately 13 hours.**

Upon successful completion of this unit, you will be able to:

- compare and contrast distance and displacement;
- define and distinguish between vector and scalar physical quantities;
- explain the relationship between instantaneous and average values for physical quantities;
- compare and contrast speed and velocity;
- solve one-dimensional kinematics problems;
- describe the effects of gravity on an object in motion;
- calculate the position and velocity of an object in free fall; and
- draw and interpret graphs for displacement and velocity as functions of time, and determine velocity and acceleration from them.

### 2.1: Vectors, Scalars, and Coordinate Systems

Please click on the link above and watch this lecture series, pausing to take notes, before moving on to the reading below.

Read sections 2.1 and 2.2 of "Chapter 2: Kinematics". Look over the corresponding conceptual questions in each section to test your understanding.

Try solving these practice problems.

### 2.2: Velocity, Speed, and Acceleration

Please click on the link above and watch this lecture series, pausing to take notes, before moving on to the reading below.

Read sections 2.3 and 2.4 of "Chapter 2: Kinematics". Look over the conceptual questions in each section to test your understanding.

Try solving these practice problems.

### 2.3: Motion with Constant Acceleration

Read sections 2.5 and 2.6 of "Chapter 2: Kinematics". Look over the conceptual questions in each section to test your understanding.

Try solving these practice problems.

### 2.4: Falling Objects

Please click on the link above and watch this lecture series, pausing to take notes, before moving on to the reading below.

Read section 2.7 of "Chapter 2: Kinematics". Look over the conceptual questions at the end of the section to test your understanding.

Try solving these practice problems.

Work on solving problems 1, 2, and 3 from 106A and 3 from 107. The solutions are available, but make a serious attempt to solve the problems before looking at the solutions.

### 2.5: Graphical Analysis

Read section 2.8 of "Chapter 2: Kinematics". Look over the conceptual questions in the section to test your understanding.

Try solving these practice problems.

Work on solving problems 1, 2, and 3 from SAC108. The solutions are available, but make a serious attempt to solve the problems before looking at the solutions.

### Unit 2 Assessment

Take this assessment to see how well you understood this unit.

- This assessment
**does not count towards your grade**. It is just for practice! - You will see the correct answers when you submit your answers. Use this to help you study for the final exam!
- You can take this assessment as many times as you want, whenever you want.

- This assessment