Lab
Index of Refraction: Water
Printer Friendly Version
Purpose:
To use ray sightings to calculate the index of refraction of water.
Equipment:
semi-circular water trough (D-cell) filled up two-thirds of the way with water
ruler
cardboard
protractor
green data paper
2 straight pins
Set-up:
Procedure:
Place the green paper on the cardboard.
Place the semi-circular water trough in the center of the green paper and trace its outline in pencil.
Asymmetrically, place the straight pins into the paper between 5 to 10 cm from the top of the trough's position.
Sight the base of the left pin through the water until the edge of the ruler "appears" to line up the pin with the scratch mark in the center of the flat side of the water trough.
Using a ruler, sketch this line on your paper - connecting it to the scratch mark on the flat side of the trough.
Repeat the above process with the right pin.
Remove the water trough and connect the line of sight for each pin to the central scratch mark on the flat side of the trough.
Measurements:
Using your protractor, measure the angle of incidence and the angle of refraction for each pin. Label your diagram and then place your answers in the data table provided. Next use
Snell's Law
to calculate the experimental index of refraction for water based on the angle data for each pin.
n
_{water}
sin(θ
_{water }
) = n
_{air}
sin(θ
_{air }
)
since n
_{air}
= 1.0
n
_{water}
= sin(θ
_{air }
)/sin(θ
_{water }
)
Data Table
left pin
right pin
air
water
experimental index
Analysis and Conclusions
Why should the rays not "bend" when they first enter the D-cell?
What is the average of your two experimental values for the index of refraction of water?
What was the percent difference between your two experimental values for the index of water?
The accepted value for the index of water is 1.33. Calculate the percent error for your average experimental index of refraction of water.
Calculate the average speed of light (in m/sec) through water using the accepted index of refraction.
Using your previous value for the average speed of light, calculate the time (in sec) required for the light to travel through the water in the D-cell.
On your papers, in addition to labelling your angles, color the rays from the left pin in color #1, the rays from the right pin in color #2, and the normal and water trough in color #3. Remember to place arrows on each ray showing that the light originated at each pin and traveled through the water to your eye.
Related Documents
Lab:
Labs -
A Simple Microscope
Labs -
Blank Ray Diagrams for Converging Lenses
Labs -
Blank Ray Diagrams for Converging, Concave, Mirrors
Labs -
Blank Ray Diagrams for Diverging Lenses
Labs -
Blank Ray Diagrams for Diverging, Convex, Mirrors
Labs -
Determining the Focal Length of a Converging Lens
Labs -
Index of Refraction: Glass
Labs -
Least Time Activity
Labs -
Man and the Mirror
Labs -
Man and the Mirror: Sample Ray Diagram
Labs -
Ray Diagrams for Converging Lenses
Labs -
Ray Diagrams for Converging Mirrors
Labs -
Ray Diagrams for Diverging Lenses
Labs -
Ray Diagrams for Diverging Mirrors
Labs -
Reflections of a Triangle
Labs -
Spherical Mirror Lab
Labs -
Student Lens Lab
Labs -
Target Practice - Revised
Resource Lesson:
RL -
A Derivation of Snell's Law
RL -
Converging Lens Examples
RL -
Converging Lenses
RL -
Demonstration: Infinite Images
RL -
Demonstration: Real Images
RL -
Demonstration: Virtual Images
RL -
Dispersion
RL -
Diverging Lenses
RL -
Double Lens Systems
RL -
Lensmaker Equation
RL -
Mirror Equation
RL -
Properties of Plane Mirrors
RL -
Refraction of Light
RL -
Refraction Phenomena
RL -
Snell's Law
RL -
Snell's Law: Derivation
RL -
Spherical Mirrors
RL -
Thin Lens Equation
Review:
REV -
Drill: Reflection and Mirrors
REV -
Mirror Properties
REV -
Physics I Honors: 2nd 9-week notebook
REV -
Physics I: 2nd 9-week notebook
REV -
Spherical Lens Properties
Worksheet:
APP -
Enlightened
APP -
Reflections
APP -
The Librarian
APP -
The Starlet
CP -
Lenses
CP -
Plane Mirror Reflections
CP -
Refraction of Light
CP -
Snell's Law
CP -
Snell's Law
NT -
Image Distances
NT -
Laser Fishing
NT -
Mirror Height
NT -
Mirror Length
NT -
Reflection
NT -
Underwater Vision
WS -
An Extension of Snell's Law
WS -
Basic Principles of Refraction
WS -
Converging Lens Vocabulary
WS -
Diverging Lens Vocabulary
WS -
Lensmaker Equation
WS -
Plane Mirror Reflections
WS -
Refraction and Critical Angles
WS -
Refraction Phenomena
WS -
Refraction Through a Circular Disk
WS -
Refraction Through a Glass Plate
WS -
Refraction Through a Triangle
WS -
Snell's Law Calculations
WS -
Spherical Mirror Equation #1
WS -
Spherical Mirror Equation #2
WS -
Spherical Mirrors: Image Patterns
WS -
Thin Lens Equation #1: Converging Lenses
WS -
Thin Lens Equation #2: Converging Lenses
WS -
Thin Lens Equation #3: Both Types
WS -
Thin Lens Equation #4: Both Types
WS -
Two-Lens Worksheet
WS -
Two-Mirror Worksheet
TB -
27B: Properties of Light and Refraction
TB -
Refraction Phenomena Reading Questions
PhysicsLAB
Copyright © 1997-2024
Catharine H. Colwell
All rights reserved.
Application Programmer
Mark Acton