LAB: REFLECTION
Please fill the blanks for full credit.
DISCUSSION
words bank: normal, angle of incidence, incident, reflected, angle of reflection, specular reflection
A light ray travels in a straight line from a source until it encounters some object. What happens next, depends on several factors, including the nature of the material making up the object, the smoothness of the surface, and the angle at which the light ray strikes the surface. If the surface is perfectly smooth, rays of light undergo _______________.
Light rays traveling from a source, before they are reflected, are called_____________ rays. If an incident ray undergoes reflection, it is called a _______________ ray. A line perpendicular to the surface, at the point where the incident ray strikes, is called the ____________.
The angle between an incident ray and the normal is called the ______________________________. The angle between a reflected ray and the normal is called the ______________________. These terms are descriptive in their meaning, but in each case you will need to remember that the angle is measured from a line perpendicular to the surface, the ________________.
PROCEDURE
step1: Using a ruler, draw a straight line across a sheet of plain (unlined) white paper. Place the paper on a smooth piece of carboard that has been cut from a box. Label the line with a B at one end and a B'at the other end. (B for boudary).
step2: Attach a small, flat mirror to a block of wood. Place the mirror and block combination on the paper with the back o f the mirror (the reflecting surface) on line BB'. (see figure).
step3: Stick a pin straight up and down into the paper about 10cm from the mirror and slightly to the right side. (see figure). On the left side, carefully align the edge of a ruler with the relected image as shown. You need to place your eye as shown. THen firmly hold the ruler and a pencil line along this edge. Move the mirror and extend this line to the mirror boundary line BB'. Label the point of reflection with the letter P.
step4: Place a protractor on line BB' and mark a point 90 degree from the line. From this point, use the ruler to draw a dashed normal (NP). Complete your ray diagram by using he ruler t draw a line from the point of reflection (P) to the sourcr of the light ray at the pin (I). Place arrows on line IP and line PR to show which way the light ray moved.
step5: Use the protractor to measure the angle of incidence and the angle of reflection. Record this angles in Data TABLE 1.
step6: Place the mirror with its back edge again on line BB'and conduct a second and third trial at different sighting angles. Record these measurements in Data table 1.
ANALYSIS
Describe any pattern you found in the data between the angle of incidence and the angle of reflection
Do you think the goal of the lab was achieved?
words bank: normal, angle of incidence, incident, reflected, angle of reflection, specular reflection
A light ray travels in a straight line from a source until it encounters some object. What happens next, depends on several factors, including the nature of the material making up the object, the smoothness of the surface, and the angle at which the light ray strikes the surface. If the surface is perfectly smooth, rays of light undergo _______________.
Light rays traveling from a source, before they are reflected, are called_____________ rays. If an incident ray undergoes reflection, it is called a _______________ ray. A line perpendicular to the surface, at the point where the incident ray strikes, is called the ____________.
The angle between an incident ray and the normal is called the ______________________________. The angle between a reflected ray and the normal is called the ______________________. These terms are descriptive in their meaning, but in each case you will need to remember that the angle is measured from a line perpendicular to the surface, the ________________.
PROCEDURE
step1: Using a ruler, draw a straight line across a sheet of plain (unlined) white paper. Place the paper on a smooth piece of carboard that has been cut from a box. Label the line with a B at one end and a B'at the other end. (B for boudary).
step2: Attach a small, flat mirror to a block of wood. Place the mirror and block combination on the paper with the back o f the mirror (the reflecting surface) on line BB'. (see figure).
step3: Stick a pin straight up and down into the paper about 10cm from the mirror and slightly to the right side. (see figure). On the left side, carefully align the edge of a ruler with the relected image as shown. You need to place your eye as shown. THen firmly hold the ruler and a pencil line along this edge. Move the mirror and extend this line to the mirror boundary line BB'. Label the point of reflection with the letter P.
step4: Place a protractor on line BB' and mark a point 90 degree from the line. From this point, use the ruler to draw a dashed normal (NP). Complete your ray diagram by using he ruler t draw a line from the point of reflection (P) to the sourcr of the light ray at the pin (I). Place arrows on line IP and line PR to show which way the light ray moved.
step5: Use the protractor to measure the angle of incidence and the angle of reflection. Record this angles in Data TABLE 1.
step6: Place the mirror with its back edge again on line BB'and conduct a second and third trial at different sighting angles. Record these measurements in Data table 1.
| TRIAL | Angle of Incidence | Angle of Reflection |
| 1 | ||
| 2 | ||
| 3 |
ANALYSIS
Describe any pattern you found in the data between the angle of incidence and the angle of reflection
Do you think the goal of the lab was achieved?