Electromagnetic waves are waves that are able to travel through a vacuum. On the contrary, mechanical waves, unlike electromagnetic waves, require the presence of medium (material) for it to transport its energy from one location to another. They all consist of a wave disturbance that repeats itself over a distance called the wavelength. The wavelength of an electromagnetic wave is inversely proportional to its frequency. As the frequency decreases, so does the energy. So waves with high frequency have short wavelengths, and waves with low frequency have long wavelengths. The following are kinds of electromagnetic waves.
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Microwaves are good for transmitting information from one place to another because microwave energy can penetrate through haze, light, rain, cloud and smoke. Microwaves work well for cooking because their energy can be efficiently absorbed by molecules commonly found in food, including water, sugars, and fats. The absorbed microwave energy heats these molecules and cooks the food.
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When performing this experiment, we will be applying our knowledge of some of the physical properties of waves (refer to previous page) to estimate the speed of light. The speed of light can be measured by the equation: v = fλ. where:
- the frequency is (f ) - wavelength is (λ) - wave speed (the speed of light) (v ) |