Question

em background information: circle key vocabulary. write one thing under the image that stands out.
what is light? it is not matter, so it cannot be a bar of matter. gamma - visible light is better understood as a
wave with a wavelength and frequency that our eyes are able to interpret. there are also other types of light,
ultraviolet, infrared and non - visible. the visible light we see is just a small part of the electromagnetic
spectrum. see the diagram below for the different types of electromagnetic radiation. the shortest waves of light
are gamma rays and the longest waves are radio waves.

questions:

1. briefly define the following parts of a wave then label them in the diagram to the right:

• wavelength -
• crest -
• amplitude -
• trough -
• frequency
• energy

1. what is frequency? do waves with higher frequency have a longer or shorter wavelength?
2. which type of electromagnetic radiation has the longest wavelength? the shortest?

Explanation:

1. Wavelength: The distance between two consecutive points in phase on a wave. On the diagram, it is the horizontal distance between two identical points (e.g., two crests).

• Crest: The highest - point of a wave. Marked at the top of the wave curve on the diagram.
• Amplitude: The maximum displacement of a wave from its equilibrium position. Measured vertically on the diagram from the equilibrium line to a crest or trough.
• Trough: The lowest - point of a wave. Marked at the bottom of the wave curve on the diagram.

1. Frequency is the number of complete waves that pass a given point in a certain amount of time. Waves with higher frequency have shorter wavelengths because the product of frequency and wavelength is the speed of the wave (a constant in a given medium), so as frequency increases, wavelength decreases.
2. Radio waves have the longest wavelength in the electromagnetic spectrum, and gamma rays have the shortest wavelength.

Answer:

1. Wavelength: Distance between two consecutive in - phase points. Marked horizontally between like - points on diagram.

• Crest: The highest point of the wave. Marked at top of wave curve.
• Amplitude: Maximum displacement from equilibrium. Marked vertically from equilibrium to crest/trough.
• Trough: The lowest point of the wave. Marked at bottom of wave curve.

1. Frequency is the number of waves per unit time. Waves with higher frequency have shorter wavelengths.
2. Radio waves have the longest wavelength. Gamma rays have the shortest wavelength.