Distance is a scalar and is ignorant of direction. On the other hand, displacement is a vector and is direction-conscious. This difference between distance and displacement affects the measurement of these two quantities whenever a motion involves a direction change.  In this activity, you will practice measuring the distance and displacement for three different motions.
Begin Activity
Vector Walk
Cross Country Skier
In this activity, you will observe the motion of a car in a parking lot, a cross country skier on a golf course, and a shopping cart moving along a grocery store aisle.  Your goal is to observe the motion and determine the overall distance and the displacement for each.
Shopping Cart in Aisle
Car in a Parking Lot
-20
10
-25
5
15
20
Start
A car in a parking lot travels back and forth in a parking lane in an effort to find a good parking place. Tap the Start button to view the motion.
25
Position (m)
-5
-10
-15
0
Repeat
Watch carefully!
Continue
You can tap the Continue button to answer questions regarding the distance and the displacement of the car. Or you can tap the Repeat button to watch the animation again.
What is the overall distance and the overall displacement for the car's motion? If you need to watch again, tap the Repeat button.
Distance (m) =
Displacement (m) =
(The answer is a multiple of 5 m. Enter a - answer where appropriate; leftward is the - direction.)
A
Answers:   distance = 130 m       displacement = 40 m, right or +40 m The distance is determined by adding up all the ground that was covered. That is, add the distances from A to B, then from B to C to D, and then from D to E. This means one must add 40 m (A to B) and 45 m (B to C to D) and 45 m (D to E). The displacment is determined by simply measuring from the starting position (A) to the final position (E). This is 40 m, directed to the right.
Return Home
B, E
C
The car traveled from A to B to C to D to E.
D
A cross-country skier is moving back and forth along a golf course.Tap the Start button to view the motion.
50
30
-40
-50
40
-30
You can tap the Continue button to answer questions regarding the distance and the displacement of the skier. Or you can tap the Repeat button to watch the animation again.
Watch carefully!
(The answer is a multiple of 5 m. Enter a - answer where appropriate; leftward is the - direction. You will have best results if you measure from the middle of the skier.)
What is the overall distance and the overall displacement for the skier's motion? If you need to watch again, tap the Repeat button.
The skier moved from A to B to C to D.
B
Answers:   distance = 165 m       displacement = 75 m, left or -75 m The distance is determined by adding up all the ground that was covered. That is, add the distances from A to B, then from B to C, and then from C to C. This means one must add 60 m (A to B) and 45 m (B to C) and 60 m (C to D). The displacement is determined by simply measuring from the starting position (A) to the final position (D). This is 75 m, directed to the left.
A grocery cart is pushed back and forth down an aisle of a grocery store. Tap the Start button to view the motion.
What is the overall distance and the overall displacement for the cart's motion? If you need to watch again, tap the Repeat button.
(The answer is a multiple of 5 m. Enter a - answer where appropriate; leftward is the - direction. You will have best results if you measure from the middle of the cart.)
(The answer is a multiple of 5 m. Enter a - answer where appropriate; leftward is the - direction. You will have best results if you measure from the middle of the cart.)
The cart moved from A to B to C to D.
Answers:   distance = 95 m       displacement = 25 m, right or +25 m The distance is determined by adding up all the ground that was covered. That is, add the distances from A to B, then from B to C, and then from C to C. This means one must add 15 m (A to B) and 35 m (B to C) and 45 m (C to D). The displacement is determined by simply measuring from the starting position (A) to the final position (D). This is 25 m, directed to the right.