Light-Energy-Exploring-the-Invisible-Force.pptx

This slide can be used as a guide to teach on light energy. Suitable for grade 6 students

1. Light Energy: Exploring the Invisible Force Light is an essential part of our world. It allows us to see, provides warmth, and powers many technologies. We can't see light energy itself, but we experience its effects all around us. by Jacob Daniel

2. Sources of Light Energy 1 The Sun Our sun is the most significant natural source of light energy. It provides light and heat to Earth, making life possible. 2 Stars Other stars in the universe also emit light energy, though they appear as tiny dots from Earth. 3 Fire Fire releases light energy as a result of a chemical reaction, producing heat and light. 4 Electric Light Light bulbs, lasers, and LEDs convert electrical energy into light energy.

3. Properties of Light Energy Speed Light travels incredibly fast, about 186,000 miles per second! This is why we see things almost instantly. Wavelength Light waves have different wavelengths, which determine the color we perceive. Shorter wavelengths appear blue, while longer wavelengths appear red. Frequency The frequency of light waves determines how much energy they carry. Higher frequency light has more energy.

4. Reflection of Light Light Strikes Surface Light energy travels in straight lines called rays. When a ray of light hits a surface, it can bounce back. Angle of Incidence The angle at which the light ray hits the surface is called the angle of incidence. Angle of Reflection The angle at which the light ray bounces back is called the angle of reflection. This angle is equal to the angle of incidence.

5. Refraction of Light 1 Light Enters Medium When light travels from one medium to another, for example, from air to water, its speed changes. 2 Path Bends This change in speed causes the light ray to bend, creating the illusion of a bent object. 3 Refraction The bending of light as it passes from one medium to another is called refraction.

6. Absorption of Light Dark Colors Dark surfaces absorb more light energy, converting it into heat. This is why black clothing is warmer in sunlight. Opaque Objects Opaque objects, like walls, block light from passing through, absorbing most of the light energy. Plant Growth Plants absorb light energy for photosynthesis, using it to create food and energy. Different wavelengths are absorbed differently.

7. Transmission of Light Transparent Materials Allow light to pass through them easily. Examples Glass, water, air Translucent Materials Allow some light to pass through, but scatter it, making images blurry. Examples Frosted glass, tissue paper

8. Applications of Light Energy Lighting Light bulbs, LEDs, and streetlights illuminate our homes, streets, and workplaces. Photography Cameras use light energy to capture images and preserve memories. Technology Fiber optic cables use light energy to transmit data at incredibly fast speeds. Solar Power Solar panels convert light energy from the sun into electricity, providing clean and renewable energy.

9. Importance of Light Energy 1 Vision Light allows us to see the world around us, enabling us to interact with our surroundings. 2 Growth Light energy is essential for plant growth through photosynthesis, providing food and oxygen for all living things. 3 Energy Light energy is a primary source of power, used in various technologies and industries.

10. Conserving Light Energy Turn Off Lights Switch off lights when leaving a room to avoid wasting energy. Use Natural Light Maximize natural light during the day by opening curtains and blinds. Energy-Efficient Bulbs Replace traditional incandescent bulbs with LED bulbs, which use less energy and last longer.