1. Kinematics Chapter 2 Conceptual Physics

2. Kinematics is the study of the motion of objects.

3. -Kinematics is the science of describing the motion of objects using words, diagrams, numbers, graphs, and equations. - Kinematics is a branch of mechanics.

4. In this lesson, we will focus on the language of kinematics. –scalars –vectors –distance –displacement –speed –velocity –acceleration

5. Scalar vs. Vector Words used to describe motion: going fast, stopped, slowing down,speeding up, and turning These words are associated with mathematical quantities with strict definitions and can be divided into Scalar or Vector

6. Scalars are quantities that are fully described by a magnitude (or numerical value) alone. Vectors are quantities that are fully described by both a magnitude and a direction.

7. Distance vs. Displacement Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion. Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position. X

8. A skier travels from A to B, realizes he dropped his glove and goes all the way back to point C, then moves forward again to point D. What is the total distance traveled by the skier? What is the skier’s displacement from his original starting position?

9. Total Distance: 420 m Displacement: 140 m to the right

10. Another example… A football coach is seen pacing the sidelines during a big playoff game. Over the course of 10 minutes, you observe him move from point A to B to C to D. What is the total distance covered by the coach (in yards)? What is the coaches displacement?

11. Total distance: 95 yards Displacement: 55 yards to the left

12. Speed vs. Velocity Speed is a scalar quantity that refers to "how fast an object is moving.“ - The rate at which an object covers distance. Velocity is a vector quantity that refers to "the rate at which an object changes its position.“ - “Speed with direction”

13. Imagine your car is moving 55 mi/hr down the highway. Is this the speed or velocity of the vehicle? Why? Now you specify that you are moving 55 mi/hr south along the highway. Is this speed or velocity? Why?

14. As an object moves, it can undergo changes in its speed. On my drive to work, I go from 0 mph to 60 mph to 45 mph to 0 mph to 30 mph to 0 mph. How could I calculate my average speed over the course of my trip?