Lesson #101 Total Distance versus Displacement

Quote of the Day:
"We use only 10% of our brains… Imagine how smart we would
    be if we used the other 60%!"  -- Ellen DeGeneres 
   
Objectives:
The student will distinguish between total distance and 
   displacement.

The student will determine displacement and total distance traveled.

1. Collect Homework.

2. Distance problem
   At 60 mph, it takes 60 seconds to travel a mile.
   At 120 mph, it takes 30 seconds to travel a mile.
   At what speed would it take 45 seconds to travel a mile?

   Ans.: 80 mph!

3. Difference between Displacement and Total Distance.
   
   Displacement is just the difference between the
   coordinate of the final point and the coordinate of the 
   initial point.

   For example, a person walks along the number line and 
   begins at the point whose coordinate is zero.  That 
   person walks 5 units to the right, then turns around and 
   walks to the left 8 units.  What is the displacement and 
   the total distance?

   Examine the diagram below.  The displacement is –3 
   because the person wound up 3 units to the left of the 
   starting point.  However, the total distance traveled is 
   13 units (5 units + 8 units).

       

4. Example
       

5. Example
       

6. Additional Examples:
       

7. Comics Strip about distance versus displacement

8. Assignment
    p. 416 (1a,b, 5a,b, 9a, 10a, 13, 32, 34, 40, 41)

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