Page 134 - Physics_Form_2

Physics for Secondary Schools

5. Now, place a burning candle
in front of board A and look
through the hole in board
C. Then, move board B
sideways slightly and again
look through the pinhole in
FOR ONLINE READING ONLY
board C.

Questions

Focusing on observations in
steps 4 and 5:
(a) What insights did you gain
from steps 4 and 5?
(b) Draw patterns or themes from
your observations in steps 4
and 5.
Figure 4.2
The rectilinear propagation of light (a) What did you observe about the path of
is a fundamental principle which the light in the straight tube?
states that light travels in straight (b) How did the light behave when it travelled
lines in a uniform medium. This through the curved tube?
principle is crucial in designing
optical devices like cameras, (c) What conclusions can you draw about
telescopes, and lasers, where how light travels through different shapes
precise light paths are necessary of tubes?
for functionality. The concept of
rectilinear propagation of light Transmission of light
helps to understand the behaviour The ability of light to travel through matter
of light, making it important in both varies from one substance to another. When
science and practical applications. light travels through matter, it is said to be
transmitted (passed through). When discussing

Task 4.2 light transmission, materials are classified into
three categories, namely: transparent materials,
Hold the straight tube in front translucent materials, and opaque materials.
of the light source and note
what you observe (Figure 4.2 Transparent materials are materials that allow
(A)). Next, hold the curved light to pass through them. You can see through
tube (Figure 4.2 (B)) in front transparent materials without obstruction, as
of the light source and again shown in Figure 4.3. These materials appear
note your observation. to be clear. Examples of transparent materials

128
Student’s Book Form Two

Physics Form 2 Final.indd 128 25/10/2025 10:27