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Remote Learning Copy Day and Night, Moon Phases

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Seasons and the Sun: Crash Course Kids 11.1

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Chemical Reactions Earth History & Fossils Ecosystems Energy Force & Motion Heat Energy Magnets and Motion Matter: Properties and Change Properties of Matter Rocks & Minerals STEM Club Weather Winning at Science

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Clouds are given different names based on their shape and their height in the sky. Some clouds are puffy like cotton while others are grey and uniform. Some clouds are near the ground, while others are near the top of the troposphere. The diagram on the right shows where different types of clouds are located in the sky.

How Are Clouds Classified?

Most clouds can be divided into groups (high/middle/low) based on the height of the cloud's base above the Earth's surface. Other clouds are grouped not by their height, but by their unique characteristics, such as those that form over mountains ( lenticular clouds) or beneath existing clouds ( mammatus clouds).

The table below provides information about cloud groups and any cloud types associated with them. Click on the cloud images in the table to learn more about each cloud type.

*Cloud heights in the table above are for the mid-latitudes. In the polar regions, the top of the troposphere is lower, so clouds are lower. In the tropics, the top of the troposphere is higher, so clouds are higher. A few other clouds are found in higher layers of the atmosphere. Polar stratospheric clouds are located in a layer of the atmosphere called the stratosphere. Polar mesospheric clouds, which are also called noctilucent clouds, are located in the atmospheric layer called the mesosphere.

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Clouds are given different names based on their shape and their height in the sky. Learn about each cloud type and how they are grouped.

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Weather Instruments: StudyJams! Science | Scholastic.com

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Every day meteorologists use tools to predict the weather. This activity will teach students about these tools and the different ways in which they are used.

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Clouds and Precipitation: StudyJams! Science | Scholastic.com

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What do the different types of clouds mean? This activity will teach students about the different types of clouds and how precipitation works.

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Wavelength is defined as the distance from a point on a wave to the corresponding point on an adjacent wave. Although the crest and trough points are easy to identify, it is important to remember that wavelength can be measured accurately from any two corresponding points.

wavelength measured from crest to crest

wavelength measured from trough to trough

Drag the ruler over the waves to help you measure their wavelengths.
Enter the lengths into the fields at right and then check your answers.

Light travels in waves, and the wavelength determines the color of light that can be observed. In the case of infrared, visible light, and ultraviolet light, the wavelength is measured in nanometers (10⁻⁹ meters).

Infrared

Visible Light

Ultraviolet

Click and drag the slider to change the wavelength and see how it varies and affects the light that we see.

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Wavelength is defined as the distance from a point on a wave to the corresponding point on an adjacent wave. Although the crest and trough points are easy to identify, it is important to remember that wavelength can be measured accurately from any two corresponding points.

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Electromagnetic Waves around of Visible Rays - JavaLab

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Electromagnetic radiation refers to the electromagnetic field waves radiating through space-time, carrying electromagnetic radiant energy. It includes radio waves, microwaves,…

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Grades 6th - 12th by Ankush Naskar

Instructions : Drag the torch to different positions to see how the light ray reflects off the mirror.

What is Reflection?

When light rays bounce off a reflective surface, it is called reflection.

What is Incident Ray? What is Reflected Ray?

A ray of light that falls on a mirror is called the incident ray. The light ray reflecting away from the mirror is called the reflected ray.

What is the Normal, Angle of Incidence and Reflection?

A normal is a line drawn perpendicular to the reflective surface at the point where incident ray hits the surface. Angle of the incident ray to the normal is called the angle of incidence. Similarly, angle of the reflected ray to the normal is called the angle of reflection.

What is the Law of Reflection?

The law of reflection states that the angle of incidence is equal to the angle of reflection when a light ray reflects off a surface.

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Play with light reflection at different angles in our interactive reflection simulation.

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mechanical wave that results from the back and forth vibration of the particles of the medium through which the sound wave is moving. If a sound wave is moving from left to right through air, then particles of air will be displaced both rightward and leftward as the energy of the sound wave passes through it. The motion of the particles is parallel (and anti-parallel) to the direction of the energy transport. This is what characterizes sound waves in air as longitudinal waves.
A vibrating tuning fork is capable of creating such a longitudinal wave. As the tines of the fork vibrate back and forth, they push on neighboring air particles. The forward motion of a tine pushes air molecules horizontally to the right and the backward retraction of the tine creates a low-pressure area allowing the air particles to move back to the left.

Because of the longitudinal motion of the air particles, there are regions in the air where the air particles are compressed together and other regions where the air particles are spread apart. These regions are known as compressions and rarefactions respectively. The compressions are regions of high air pressure while the rarefactions are regions of low air pressure. The diagram below depicts a sound wave created by a tuning fork and propagated through the air in an open tube. The compressions and rarefactions are labeled.

The wavelength of a wave is merely the distance that a disturbance travels along the medium in one complete wave cycle. Since a wave repeats its pattern once every wave cycle, the wavelength is sometimes referred to as the length of the repeating patterns - the length of one complete wave. For a transverse wave, this length is commonly measured from one wave crest to the next adjacent wave crest or from one wave trough to the next adjacent wave trough. Since a longitudinal wave does not contain crests and troughs, its wavelength must be measured differently. A longitudinal wave consists of a repeating pattern of compressions and rarefactions. Thus, the wavelength is commonly measured as the distance from one compression to the next adjacent compression or the distance from one rarefaction to the next adjacent rarefaction.

What is a Pressure Wave?

Since a sound wave consists of a repeating pattern of high-pressure and low-pressure regions moving through a medium, it is sometimes referred to as a pressure wave. If a detector, whether it is the human ear or a man-made instrument, were used to detect a sound wave, it would detect fluctuations in pressure as the sound wave impinges upon the detecting device. At one instant in time, the detector would detect a high pressure; this would correspond to the arrival of a compression at the detector site. At the next instant in time, the detector might detect normal pressure. And then finally a low pressure would be detected, corresponding to the arrival of a rarefaction at the detector site. The fluctuations in pressure as detected by the detector occur at periodic and regular time intervals. In fact, a plot of pressure versus time would appear as a sine curve. The peak points of the sine curve correspond to compressions; the low points correspond to rarefactions; and the "zero points" correspond to the pressure that the air would have if there were no disturbance moving through it. The diagram below depicts the correspondence between the longitudinal nature of a sound wave in air and the pressure-time fluctuations that it creates at a fixed detector location.

The above diagram can be somewhat misleading if you are not careful. The representation of sound by a sine wave is merely an attempt to illustrate the sinusoidal nature of the pressure-time fluctuations. Do not conclude that sound is a transverse wave that has crests and troughs. Sound waves traveling through air are indeed longitudinal waves with compressions and rarefactions. As sound passes through air (or any fluid medium), the particles of air do not vibrate in a transverse manner. Do not be misled - sound waves traveling through air are longitudinal waves.

Check Your Understanding

1. A sound wave is a pressure wave; regions of high (compressions) and low pressure (rarefactions) are established as the result of the vibrations of the sound source. These compressions and rarefactions result because sound

a. is more dense than air and thus has more inertia, causing the bunching up of sound.

b. waves have a speed that is dependent only upon the properties of the medium.

c. is like all waves; it is able to bend into the regions of space behind obstacles.

d. is able to reflect off fixed ends and interfere with incident waves

e. vibrates longitudinally; the longitudinal movement of air produces pressure fluctuations.

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Physics Tutorial: Sound Waves as Pressure Waves

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Sound waves traveling through a fluid such as air travel as longitudinal waves. Particles of the fluid (i.e., air) vibrate back and forth in the direction that the sound wave is moving. This back-and-forth longitudinal motion creates a pattern of compressions (high pressure regions) and rarefactions (low pressure regions).

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Weather vs. Climate: Crash Course Kids #28.1