1. Distance & Displacement
Aim: How can we distinguish between distance and displacement?

2. Scalar vs. Vector Scalar Vector
A measured quantity that has MAGNITUDE but NO DIRECTION
Magnitude = Size/Value
Can only be a POSITIVE value
Vector
A measured quantity that has MAGNITUDE & DIRECTION
Usually represented by an ARROW
Can be POSITIVE or NEGATIVE

3. The MADFIVE Momentum Acceleration Displacement Force Impulse Velocity
All the VECTORS you need to know for Physics
Momentum
Acceleration
Displacement
Force
Impulse
Velocity
Electromagnetism
Anything else outside of this list is a SCALAR

4. Distance vs. Displacement
Scalar
The TOTAL length of the path that an object travels
Displacement
Vector
The STRAIGHT LINE path between the object’s origin and its final position
Distance
Displacement
Start
Finish

5. Sign Convention for Vectors
Positive Up
Right
North
East
Negative
Down
Left
South
West
Helpful Tip: Whenever dealing with any sort of physics problem, especially ones that deal with a moving object, it is very advantageous to sketch a diagram

6. Examples A bird flies 50m north A ball rolls 7m left
Distance =
Displacement =
A ball rolls 7m left
A child jumps 2 meters straight up from the edge of a pool, does a cannonball, and stops one meter below the surface of the water
50m
+50m OR 50m north 7m
-7m OR 7m left 5m
-1m OR 1m down

7. Example #4 21 blocks 15 blocks NW 44 blocks
In order to get to work, a woman in the city needs to walk 9 blocks north then 12 blocks west. What is the woman’s (a) distance and (b) displacement? Before returning home after work, she visits her favorite Indian restaurant that is 10 blocks south of her job. What is the woman’s (c) total distance and (d) final displacement when she arrives home?
12 blocks
21 blocks
15 blocks NW
44 blocks
9 blocks
10 blocks
1 block
12 blocks

8. SUMMARY Define Scalar Define Vector
How can you memorize all of the vectors?
Identify them
Define Distance
Define Displacement
Describe the sign convention