2. Light Energy and its sources
• Light is a form of energy that can be observed
by the human eye.
• Luminous objects emit light and nonluminous
objects reflect light.
3. Types of Light
• Incandescence-high temperature creates luminous light
• Phosphorescence-stores energy that is slowly released as light
energy.
• Electric Discharge-Electricity passes through gas and emits light.
• Fluorescence-electrical energy flows through a gas, causing it to
emit ultraviolet light
• Chemiluminescence – chemical reaction emits light
• Bioluminescence- emission of light by a living organism as the
result of a chemical reaction
4. Travelling Light
• Light travels in a straight path
• Transparent objects allow light to pass through
easily.
• Translucent objects allows some light through and
reflects some.
Translucent Frogs
• Opaque objects do not allow any light to pass
through. All light energy is absorbed or reflected.
• Translucent, Transparent and Opaque
5. Visible Spectrum
• Red
• Orange
• Yellow
• Green
• Blue
• Violet
• White- all light is reflected
• Black- all light is absorbed.
• Objects have the colour of the light that is reflected
from their surface. All the other light is absorbed.
6. Waves
• A wave is a result of a vibration that transfers
energy from one location to another.
• Amplitude indicates amount of energy
transferred. Larger=Louder, More Energy
• Wavelength over a period of time indicates the
frequency. A higher frequency will penetrate objects
much easier and have a higher energy.
• Oscilloscope Demo
Distance between 2 crests or troughs
Highest point
Lowest point
Maximum distance
from resting point
7. Electromagnetic Spectrum
• Radiant energy emitted by all matter whose
temperature is greater than absolute zero (0°
K).
• The warmer the radiant object, the shorter
the frequency of electromagnetic waves it
emits.
• Electromagnetic Spectrum Song
8. Solar Panels
• A solar cell or photovoltaic cell is a device that
converts sunlight directly into electricity.
• A solar panel is a collection of solar cells.
• Solar Car
