Distance vs. Displacement

Distance: the length of a path

Ex: You walk 50 m East from physics to Mrs. York’s class but you find you forgot your agenda in physics so you walk back to retrieve it.

50m E

Total distance? 50m + 50m= 100m

50m WPhysics

Mrs. York’s

Physics

A straight arrow from start to finish: “As a crow flies” Make sure you have direction with

answer.

Displacement

50m E

0m

50m W

Start and stopping point are the same so displacement =

N

W

S

E

Mrs. York’s

Distance: the length of a path

Ex: A pigeon runs 75 m east along Harding’s rooftop. It takes a break and then runs 47 m south. The pigeon then runs 75m west. Total distance? 75 + 47 + 75= 197m

47m S

75m E

75m W

Displacement: from start to finish

Ex: A pigeon runs 75 m east along Harding’s rooftop. It takes a break and then runs 47 m south. The pigeon then runs 75m west.

75m E

Displacement?

47m S

75m W

Draw your

displacement line from tail to tip!

47m S

75m E

75m W

?

Distance: the length of a path

2km

S

Ex: A hippopotamus swims 2 km south in the river, walks 1 km west then proceeds 1 km north.

1km W

1km

N

Total distance? 2km + 1km +1km =

4km

Displacement

2km

S

Make sure your answer has a direction.

1km W

1km

N

Total displacement?

Use

Geometry!

Displacement

2km

S

1km W

1km

N

?

?

?

1km

1km

Displacement

?

1km

1km

1.41km SW

How do you find the hypotenuse of a right

triangle?

a2 + b2 = c2

12 + 12 = c2

1 + 1 = c2

√2 = c