In the classroom, students review the properties of waves. On the field trip, students investigate what objects absorb and retain the most heat, and then use sound waves to find local birds. They observe how lenses change light waves, discovering how common objects use lenses to bend light to meet our needs, and they investigate how sunscreen blocks UV waves. Back in the classroom, students discuss when our use of heat, light, or sound waves becomes overuse.Energy is transported around the universe in the form of waves. Sound waves, light waves, ocean waves, heat waves, and radio waves are some examples. The shape of the wave determines its characteristics. The amplitude is the height of the wave. The crest is the top of the wave. The trough is the bottom of the wave. Frequency is the number of times the wave crests in a given period. Wavelength is the distance between two crests. The speed of the wave is determined by multiplying the frequency times its wavelength. If the crest on one wave occurs at the same time and place as a trough in another wave they are considered out of phase. These waves can interfere with each other or even cancel each other out.
Sound travels in waves. Sound is created by the vibrations or the back and forth movement of objects. When an object vibrates, it sends sound waves off in all directions. However, sounds waves can only travel through mediums such as air, water, and objects. In other words, sound cannot travel in a vacuum. Sound waves travel at different speeds trough different mediums. The denser the material, the faster the wave travels. Pitch is the highness or lowness of a sound as we hear it. High-pitched sounds have a high frequency, and low-pitched sounds have a low frequency. Humans and animals communicate, or express their thoughts, by vibrating their vocal cords. Thicker cords vibrate more slowly and have a lower pitch. Similarly, the thicker strings on stringed instruments vibrate more slowly and produce deeper pitched tones. As boys get older, their vocal cords thicken and their voice drops. The intensity or the amplitude of the sound wave determines loudness.
The sun emits electromagnetic radiation in the form of waves. This radiation travels out from the sun in straight lines in all directions. A small portion of this radiation reaches the earth. We see small portions of this radiation as visible light. Television signals, radio waves, X-rays, Ultraviolet rays, microwaves, and infrared radiation have wavelengths that are either too short or too long for us to see. Upon encountering an object, light waves can be refl ected, refracted, or absorbed. When light is reflected, it is bent. The angle at which the light is reflected depends on the shape of the surface it is reflected from and the angle at which the light strikes the surface. Many objects that appear to produce light are only reflecting the light of another object. When light travels through a transparent object, it is bent or refracted. The shape of the object determines how the light is bent. Prisms, and sometimes water drops, bend light so that the different wavelengths are separated. Lenses bend light so that objects appear larger or smaller depending on the shape of the lens. Humans have created many different types of lenses that help us to explore and understand the world around us (Atwater et al, 1993).
Another way we perceive radiant energy is in the form of heat. Heat moves from one object to another by conduction, convection, or radiation. Conduction is the transfer of heat from one substance to another by direct contact. When either fast or slow moving particles touch one another, energy is transferred. Slow moving particles speed up, and fast moving particles slow down. Convection is the circulation of heat within liquids or gasses. Heating substances causes convection. When the particles begin to move faster, they get lighter and rise, allowing space for denser, cooler substances to fall. Radiation is the transfer of heat through open space in the form of waves. All warm objects emit heat waves or radiate (Utah State Offi ce of Education, 2002).
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Answer:
In the classroom, students review the properties of waves. On the field trip, students investigate what objects absorb and retain the most heat, and then use sound waves to find local birds. They observe how lenses change light waves, discovering how common objects use lenses to bend light to meet our needs, and they investigate how sunscreen blocks UV waves. Back in the classroom, students discuss when our use of heat, light, or sound waves becomes overuse.Energy is transported around the universe in the form of waves. Sound waves, light waves, ocean waves, heat waves, and radio waves are some examples. The shape of the wave determines its characteristics. The amplitude is the height of the wave. The crest is the top of the wave. The trough is the bottom of the wave. Frequency is the number of times the wave crests in a given period. Wavelength is the distance between two crests. The speed of the wave is determined by multiplying the frequency times its wavelength. If the crest on one wave occurs at the same time and place as a trough in another wave they are considered out of phase. These waves can interfere with each other or even cancel each other out.
Sound travels in waves. Sound is created by the vibrations or the back and forth movement of objects. When an object vibrates, it sends sound waves off in all directions. However, sounds waves can only travel through mediums such as air, water, and objects. In other words, sound cannot travel in a vacuum. Sound waves travel at different speeds trough different mediums. The denser the material, the faster the wave travels. Pitch is the highness or lowness of a sound as we hear it. High-pitched sounds have a high frequency, and low-pitched sounds have a low frequency. Humans and animals communicate, or express their thoughts, by vibrating their vocal cords. Thicker cords vibrate more slowly and have a lower pitch. Similarly, the thicker strings on stringed instruments vibrate more slowly and produce deeper pitched tones. As boys get older, their vocal cords thicken and their voice drops. The intensity or the amplitude of the sound wave determines loudness.
The sun emits electromagnetic radiation in the form of waves. This radiation travels out from the sun in straight lines in all directions. A small portion of this radiation reaches the earth. We see small portions of this radiation as visible light. Television signals, radio waves, X-rays, Ultraviolet rays, microwaves, and infrared radiation have wavelengths that are either too short or too long for us to see. Upon encountering an object, light waves can be refl ected, refracted, or absorbed. When light is reflected, it is bent. The angle at which the light is reflected depends on the shape of the surface it is reflected from and the angle at which the light strikes the surface. Many objects that appear to produce light are only reflecting the light of another object. When light travels through a transparent object, it is bent or refracted. The shape of the object determines how the light is bent. Prisms, and sometimes water drops, bend light so that the different wavelengths are separated. Lenses bend light so that objects appear larger or smaller depending on the shape of the lens. Humans have created many different types of lenses that help us to explore and understand the world around us (Atwater et al, 1993).
Another way we perceive radiant energy is in the form of heat. Heat moves from one object to another by conduction, convection, or radiation. Conduction is the transfer of heat from one substance to another by direct contact. When either fast or slow moving particles touch one another, energy is transferred. Slow moving particles speed up, and fast moving particles slow down. Convection is the circulation of heat within liquids or gasses. Heating substances causes convection. When the particles begin to move faster, they get lighter and rise, allowing space for denser, cooler substances to fall. Radiation is the transfer of heat through open space in the form of waves. All warm objects emit heat waves or radiate (Utah State Offi ce of Education, 2002).
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