Distance and Displacement

Distance and Displacement

Scalar vs. vector

• A quantity that is ignorant of direction is referred to as a _________________.

• A quantity that is conscious of direction is referred to as a _________________. 

What distance did Tim travel?  What was Tim’s displacement?

Distance vs. Displacement

• A football coach paces back and forth along the sidelines- the coach moves from position A to B to C to D. What is his distance covered and displacement?

Distance vs. Displacement

• Look at the picture given below. An object moves from point A through B, C, D, E and stops at point F. a) Find final displacement. b) Find the distance that is taken from point A to D. 

Distance and Displacement

• Displacement = Final position - Initial position

• Displacement = 10m - 2m = 8m

• We find distance taken by object;

• A to B =10 - 2 = 8m

• B to C = 10 - 2 = 8m

• C to D = 10 - 6 = 4m

• Total distance taken from point A to D is = 8m + 8m + 4m =20m. 

Distance vs. Displacement

• What are the distance and the displacement of the race car drivers in the Indy 500?

• The displacement of the cars is somewhere near 0 miles since they virtually finish where they started. Yet the successful cars have covered a distance of 500 miles.

Summary:

• Displacement is a vector quantity that refers to the shortest distance between the object’s two positions, like the distance between its point of origin and its point of destination, no matter what path it took to get to that destination. 

• Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion. The total length covered by the moving body or the entire path that the object traveled.