Distance & Displacement

Distance vs Displacement

Distance

• total length of a path from starting point to finishing point

• value can never be negative

• can happen in any direction

• can either be equal to or greater than the value of displacement

• magnitude of the length traveled; example 5 meters

Multiple Choice

Find the distance Sara walks from A to B,  B to C then C to D?

• 11m

• 3m

• 5m

Multiple Choice

Jerry walked from home to school, then from the school to the park. What is his total distance?

• 2 km

• 5 km

• 8 km

• 10 km

Displacement

• direct distance between two points

• can be negative or positive

• total distance determines how far the object has traveled from its original location

• it is always less than the distance covered by an object under consideration

• it always happens in a specific direction

Scalar vs Vector

• Scalar - a quantity, such as distance, that has magnitude (size) but does not take into account direction

• Vector - a quantity, such as displacement, that has both magnitude (size) and direction

• Vectors in the same directions are added together

• Vectors in opposite directions are subtracted

  
  

Multiple Choice

Sara walks from Point A to Point B. Which is true?

• Distance and displacement are EQUAL

• Distance is less than displacement

Multiple Choice

A car drives 84 meters forward.  It's displacement and distance would be the same.

• True

• False

Multiple Choice

Jerry walked from home to school, then from the school to the park. What is his total displacement?

• 2 km

• 5 km

• 8 km

• 10 km

Multiple Choice

A person walks 50 meters directly north, stops, and then travels 32 meters directly south.  What is their displacement?

• 82 meters

• 18 meters

• 28 meters

Frame of reference

• system of objects that are not moving with respect to one another

• describes the relative motion of an object accurately and completely

• example: a frame of reference is something not moving that is used to compared to something that is moving to determine the objects speed

Multiple Choice

Bill runs 400 meters to Andy's house, turns around, and runs 400 meters back home.  What is Bill's displacement?

• 0 meters

• 400 meters

• 800 meters

• 1600 meters

Multiple Choice

Bill runs 400 meters to Andy's house, turns around, and runs 400 meters back home.  What is Bill's distance?

• 0 meters

• 400 meters

• 800 meters

• 1600 meters

Open Ended

According to my frame of reference, you are moving as you read this question. What is my frame of reference?

Multiple Choice

A place or object (like a stop sign or mailbox) used for comparison to determine if another object is in motion is called a

• comparison point

• frame of reference

• point of view

• motion detector

Multiple Choice

David walks 3 km north, and then turns east and walks 4 km. What is the distance?

• 7 km

• 3 km

• 4 km

• 1 km

Multiple Choice

 Jermaine runs exactly 2 laps around a 400 meter track. What is the displacement?

• 800

• 400

• 0

• 200

Multiple Choice

Rachel walks 12 feet from her locker to her class, remembers that she forgot her calculator and walks back to her locker. Then she walks back to class. What was her displacement?

• 36 feet

• 24 feet

• 0 feet

• 12 feet