Chanice drives her scooter 7 km north. She stops for lunch and then drives 5 km east. What was her displacement?

Question

This is a physics question that incloves 1D kinematics. 

Answer 1

Displacement is not the distance Chanice drove, but rather the distance she is located away from her starting point. It might be easier to remember this by thinking is "displaced" from her original location.

 

The easiest way to set this up might be to draw a picture on graph paper. Since she drove 7km north, draw a vertical line 7 boxes tall (each box = 1 km). Since she drove 5 km east, draw a horizontal line (starting from the top of the 7km line) 5 boxes long. Connect the two lines to form a triangle. So you know the length of two sides of the triangle, but you need the length of the hypotenuse (which is also the displacement).

 

To find the length of one missing side in a triangle, you can use the Pythagorean Theorem:

 

a² + b² = c²

 

7² + 5² = c²

 

49 + 25 = c²

 

74 = c²

 

√74 = c²

 

c ≈ 8.60 km

 

8.60 km is Chanice's approximate displacement.