Science 10

1. Prepared by:
Ms. Jasmine Nikki M. Versoza

2.  Form of energy
 Travels in a straight line
 Forms shadow

3. LIGHT
The frequency of a light wave
varies inversely to its
wavelength and varies directly to
its energy.

5. EXAMPLE PROBLEM 1
What is the wavelength of a
electromagnetic wave that has
an frequency of 5.75 𝑥 1014
𝐻𝑧?

7. LIGHT
In computing for the energy of
a light wave, Planck’s
constant should be used

8. 𝑬 = 𝒉𝒇
E = energy in Joules (J)
h = Planck’s constant
(6.626 𝑥 10−34
𝐽. 𝑠)
f = frequency

9. EXAMPLE PROBLEM 2
What is the wavelength of an
electromagnetic wave having
7.30 𝑥 10−14
𝐽 of energy?

11. LUMINOUS OBJECTS
 Objects that emit light
 The light reaches our
eyes so we can see

12. NONLUMINOUS OBJECTS
 Objects that do not emit light
 Illuminated by light from
other sources

13. TRANSPARENT MATERIALS
Materials that allow
light to pass through

14. OPAQUE MATERIALS
 Materials that does not
allow light to pass through
 Light bounces off

15. Reflection
A property of light
Bouncing back of light
once it hits a reflective
surface.

16. Types of Reflection
1.Regular or Specular
Reflection
2.Diffused Reflection

18. The Law of Reflection
The angle of incidence is
equal to the angle of
reflection

20. TAKE NOTE:
 The normal line is always drawn
perpendicular with the reflecting
surface.
 Angle of incidence and reflection
is measured from the normal line.

21. The Law of Reflection
SAMPLE PROBLEM ONE:
A light ray strikes a reflective plane surface at an angle
of 65° with the surface.
a) Find the angle of incidence.
b) Find the angle of reflection.
c) Find the angle made by the reflected ray and the
surface.
d) Find the angle made by the incident and reflected rays.

22. In a laboratory, May arranges
two mirrors with a right angle
orientation as shown. May then
directs a laser line at one of the
mirrors. The light reflects off
both mirrors as shown. If angle
A is 54°, then what is the angle
measure of angles B, C, and D
and E?
Practice Exercise 1

23. A ray is approaching a set of three mirrors.
The light ray is approaching the first mirror at
an angle of 45-degrees with the mirror
surface. Trace the path of the light ray as it
bounces off the mirror. Continue tracing the
ray until it finally exits from the mirror system.
How many times will the ray reflect before it
finally exits?
Practice Exercise 2

25. Three initially parallel rays of light are incident at slightly
different points on a bumpy surface. The angles of
incidence are 15° for ray A (blue), 31° for ray B (green),
and 47° for ray C (red).
a. What are the angles of reflection for the three rays?
b. Will the three rays remain parallel after reflection.
Why?
c. Sketch the path of the reflected rays on the diagram.
Practice Exercise 3

26. Multiple Reflection
of Light
When light hits reflecting
surface several times, multiple
images will be formed.

27. Multiple Reflection
of Light
If the angle between two reflecting
surfaces decreases, the number
of images formed increases.

28. 𝑛𝑜. 𝑜𝑓 𝑖𝑚𝑎𝑔𝑒𝑠 =
360
𝜃
− 1
𝜃 = angle between two mirrors
Multiple Reflection
of Light

29. Multiple Reflection: Guide Questions
1. What did you see when you put
something between the mirrors?
2. What happen when you make the
angle of the mirrors greater?
3. What happen when you make the
angle of the mirrors smaller?

30. Multiple Reflection: Guide Questions
4. What is the independent variable in this
experiment?
5. What is the dependent variable in this
experiment?
6. What is the relationship between the
angle of the mirrors and the number of
images seen?

31. Multiple Reflection Activity:
ANSWERS
1. What did you see when you put
something between the mirrors?
An image is formed when I put
a coin in between the two
mirrors.

32. 2. What happens when you make the
angle of the mirrors greater?
When the angle of the two mirrors are
made greater, the lesser image are
formed.
Multiple Reflection Activity:
ANSWERS

33. 3. What happens when you make the
angle of the mirrors smaller?
When the angle of the mirrors are
made smaller, more images are
formed.
Multiple Reflection Activity:
ANSWERS

34. 4. What is the independent variable in this
experiment?
The independent variable in the
experiment is the angle of the two
mirrors.
Multiple Reflection Activity:
ANSWERS

35. 5. What is the dependent variable in this
experiment?
The dependent variable in the
experiment is the number of images
formed.
Multiple Reflection Activity:
ANSWERS

36. 6. What is the relationship between the angle of the
mirrors and the number of images seen?
The relationship between the angle and the number
of images seen is inversely proportional. Because
as the angle of the mirrors increases, the number
of images formed in the mirror decreases.
Multiple Reflection Activity:
ANSWERS