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

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

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

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

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

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

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

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