2. Unit 5: Evolution of Technology in Science
Topic: Waves
Learning Target: I can…
State what a wave is and explain how waves transport energy
Describe the properties of waves
Standard(s):
MS-PS4-1. Develop a model and use mathematical representations to describe waves that include frequency, wavelength, and how the amplitude of a wave is related to the energy in a wave.

3. Homework In 1 paragraph state and explain what the wave speed equation is? Problem of the Day What causes the signal from your cell phone to travel to another cell phone?

4. Discussion Questions
What is a wave?
Does water waves carry energy?
How does waves make your TV work?
Turn to p. 212 in text

5. Waves
A wave is a disturbance that moves through matter or space. A wave carries energy from one place to another. There are 2 main types of waves, mechanical waves and electromagnetic waves. Mechanical waves can only travel through matter. They cannot travel through space. Transverse waves and compressional (longitudinal) waves are mechanical waves.

6. Transverse Waves
A transverse wave is a mechanical wave that can only travel through matter. Transverse waves causes particles in matter to move back and forth at right angles to the direction in which the wave travels.

7. Compressional (Longitudinal) Waves
A compressional wave (longitudinal) wave is a mechanical wave that can only travel through matter. Compressional waves causes particles in matter to move back and forth along the same direction in which the waves travels. Sound is a compressional wave.

8. Properties of Waves
Properties of waves include wavelength, frequency, and amplitude. Wavelength is the distance between 2 crests or 2 troughs on a wave. Frequency is the number of wavelengths that pass a point each second. Amplitude is the height or depth of a crest or trough on a transverse wave.
Compressional Waves

9. Properties of Waves
Compressional waves with tightly squeezed compressions and more spread apart rarefactions have greater amplitude. Waves with larger amplitudes carry more energy than waves with smaller amplitudes.

10. Electromagnetic Wave
Electromagnetic waves consists of 2 transverse waves. They have an electric part and a magnetic part. The 2 waves vibrate at right angles (perpendicular) to the wave motion. Light is made up of electromagnetic waves. The frequency of light is very high. The intensity of light is a measure of the amount of energy the waves carry. Intensity determines the brightness of light: bright light has high intensity & more energy and vice versa. Electronic signals are sent as electromagnetic waves.

11. Electromagnetic Spectrum
The electromagnetic spectrum is the complete range of electromagnetic waves. The spectrum consists of radio waves, microwaves, infrared waves, visible light, ultraviolet waves, x-rays, gamma rays.

12. Lab Activity
We are now going to perform an activity/experiment in which we will observe and visualize FM radio signals (waves) in the air around us. We will use a computer, an ADALM-PLUTO Transceiver and antenna. The PLUTO receiver and antenna will generate an electrical current matching the electromagnetic wave that hit it, and a small circuit that will transform the signals (wave) it receives into digital format for the computer to read and display. The materials are already assembled on your desks. Get ready and wait for your teacher to tell you to begin