1. Speed and Velocity

2. Speed is a scalar quantity that tells how fast an object is moving or the rate at which an object covers a distance.
Average speed equals distance traveled divided by the time of travel

3. Velocity is a vector quantity and is the rate at which an object changes its position
Velocity always gives a direction
Average velocity equals the change in position divided by the time or average velocity equals displacement divided by time

4. Practice problem: While on vacation, Lisa Carr traveled a total distance of 440 miles. Her trip took 8 hours. What was her average speed?

5. Average Speed vs. Instantaneous Speed
Instantaneous speed – the speed at any given instant
Average speed – the average of all instantaneous speeds; found simply by a distance/time ratio

6. Practice Problem: Lets consider the motion of that physics teacher again. The physics teacher walks 4 meters East, 2 meters South, 4 meters West, and finally 2 meters North. The entire motion lasted for 24 seconds. Determine the average speed and average velocity.

7. Use the diagram to determine the average speed, and the average velocity of the skier.

8. Recall the pacing coach from the problem yesterday
Recall the pacing coach from the problem yesterday. What is the coach’s average speed and average velocity?

9. 1. Calculate the average speed (in meters/sec) if a golf cart runs 140 meters in 10 seconds
2. Calculate the average speed (in Km/hr) of Charlie who runs to the store 4 Km away in 30 minutes?
3. Calculate the distance (in Km) that Charlie runs if he maintains the average speed from question 2 for 1 hour

10. 4. A bicycle rider travels 50. 0 Km in 2. 5 hours
4. A bicycle rider travels 50.0 Km in 2.5 hours. What is the cyclist’s average speed?
5. What is the average speed (in miles per hour) of the car that traveled a total of 200 miles in 5.5 hours.

11. 6. How much time would it take for the sound of thunder to travel 2000 meters if sound travels a speed of 330 meters per sec.
7. How much time would it take for an airplane to reach its destination if it traveled at an average speed of 790 Km/hr for a distance of 5000 kilometers?

12. 8. An ant can travel approximately 30 meters per minute
8. An ant can travel approximately 30 meters per minute. How many meters could an ant move in 45 minutes?
9. If humans originated in Africa and migrated to other parts of the world, some time would be required for this to occur. At the modest rate of one kilometer per year, how many centuries would it take for humans originating in Africa to travel to China, some 10,000 Kilometers away?