Learn more about "The Law of Reflection" in level 1 of Putter King's physics education series.

1. All materials copyright © 2011
Putter King LLC
All rights reserved
Unit #: 2011020102
Putter King LLC
Level 28 Shinagawa Intercity Tower A
2-15-1 Konan Minato-ku Tokyo, Japan
〒108-6028
Future KingsTM Education Program
Subject: Physics
Level 1 (Prince)
For the teacherʼs guide and all answers
please contact info@putterking.com

2. Physics
Level 1 - Prince
2

3. 3
Area of focus: The Law of Reflection
Topics covered:
• Surface normal
• Angle of incidence
• Angle of reflection
• The Law of Reflection
Suggested time to complete (2 hrs):
• Teaching material (20 minutes)
• Practice activity (40 minutes)
• Final project (60 minutes)
Summary

4. 4
Surface Normal
A surface normal to a flat surface is a vector
that is perpendicular to that surface.
normal
The dotted line is perpendicular
to the flat surface.

5. 5
Angle of Incidence
The angle of incidence θi of a ray is the angle
measured from the ray to the surface normal.
θi
normal

6. 6
Angle of Reflection
The angle of reflection θr of a ray is the angle
measured from the reflected ray to the surface normal.
θr
normal

7. 7
The Law of Reflection
When a ray of light reflects off a surface,
the angle of incidence is equal to the angle of reflection.
θi = θr
θrθi
normal
The Law of Reflection describes a property of light; however, we can use the Law of Reflection to
estimate the direction of our shots in games such as miniature golf and billiards if we assume that the
there is no spin and the shot is at a low to medium strength.

8. 8
Practice Activity
Correctly draw and label the shot path to get
a hole-in-one from the “X”. Be sure to use a
protractor to correctly measure and label all
angles.
Bonus points if you can find 2 unique paths to
the hole.

9. 9
Requirements
Design and label a miniature golf hole that includes:
• the shot path to get a hole-in-one using the Law of Reflection
For full points, be sure to:
• label all angles along the shot path
• draw and label the surface normal for each angle of incidence
and angle of reflection along the shot path
• use a protractor to accurately measure all angles
• be creative!
Final Project

10. 10
Grading Rubric
Bogey
(70% - 79%)
Par
(80% - 89%)
Birdie
(90% - 100%)
Shot Path • Student shot path does not
follow the Law of Reflection
• Student shot path follows the
Law of Reflection; however,
student has made a calculation
error
• Student shot path follows the
Law of Reflection and is
accurately calculated from tee
box to hole
Labels
• Student incorrectly labeled
more than one angle
• Student incorrectly labeled the
surface normals
• Student incorrectly labeled an
angle or a surface normal
• Student correctly labeled all
angles
• Student correctly labeled the
surface normals
Design
• Miniature golf hole design is
plain and simple
• Student lines and angles are
sloppy or incorrectly labeled
• Miniature golf hole design
does not exhibit creativity
• Miniature golf hole design is
playable
• Student lines and angles are
neatly drawn and labeled
• Miniature golf hole design is
playable and aesthetically
pleasing
• Student lines and angles are
neatly drawn and labeled
• Miniature golf hole design is
creative and original