Questions – PASCO OS-8459 Beginning Optics System User Manual

Page 8

B e g i n n i n g O p t i c s S y s t e m

E x p e r i m e n t 1 : C o l o r A d d i t i o n

Part 2: Observing Colored Ink Under Colored Light

Procedure

While you look away, have your partner draw two lines—one red and one
black—on a sheet of white paper. One of the lines should be labeled A, and the
other B, but you should not know which is which.

Before you look at the paper, have your partner turn off the room lights and cover
the red and green bars so the paper is illuminated only with blue light.

Now look. What colors do the two lines appear to be? Do they appear to be
different colors? Record your observations in Table 1.2.

Finally, observe the lines under white light and record their actual colors in Table
1.2.

Repeat step 1, but this time have your partner draw lines using blue and black ink
(labeled C and D), and observe them under red light.

For Trial 2, switch roles and repeat steps 1 and 2 with the your partner observing
lines that you have drawn. Record the results in Table 1.2. (For this trial, you may
try to trick your partner by drawing both lines the same color—both red or both
black, for instance.)

Look a red line and black lines under red light. Which line is easier to see?
_________________________

Questions

What makes red ink appear red? When red ink is illumined by blue light, is most
of the light absorbed or reflected?

When illumined with red light, why is red ink on white paper more difficult to
see than black ink?

Table 1.2: Colored Ink Observed Under Colored Light

Trial 1: Name of observer: ______________________________________

Color of Light

Line

Apparent Color of Ink

Do they look different?

Actual Color of Ink

Blue Light

Red Light

Trial 2: Name of observer: ______________________________________