Light & sound by Marcos
- 1. Marcos Sánchez Herrero, 6ºB Abril 2013
- 2. What is light? • Light is a form or energy. • We can see objects because they reflect light. • Light can be: natural or artificial. How does light travel? o Light travels in straight lines and in all directions from the source of light. o Light travels at 300.000 km/sc.
- 3. The effect of light of materials. Light passes Only part of the light passes Light does not pass
- 4. The properties of light. Reflection. Reflection lets us see objects that do not emit light. Refraction. - When a ray of light goes from air to water, its speed changes and its path. - Light reflects when it passes through a lens. - Lenses can be converging an diverging. Diverging lenses make rays separate. Converging lenses make rays come together.
- 5. The uses of lenses. Glasses and contact lenses. Projectors. Telescopes and binoculars. Magnifying glasses and microscopes.
- 6. What is sound? Sound is a form of energy produced by vibrations. The characteristics of sound 1. Intensity: Sounds can be soft or loud. 2. Pitch: Can be high or low. 3. Timbre: Is the quality of a sound. How does sound travel? Sound travels in all directions and in a straight line. Sound is slower than light. It travels at 340 m/sc.
- 7. Echo and reverberation. Sound travels in waves. When the sound waves reach an obstacles, they reflect in two different ways: 1. Echo happens when the obstacle is more than 17 metres away. We hear a different in time between the sound and its reflection. 2. Reverberation happens when the obstacle is a shorter distance away. The reflected sound mixes with the emitted sound.