Waves Target Concept

Mechanical Waves

1. Definition of a wave

   1. What makes a wave a wave?

      • A wave is a disturbance that travels through space and matter, transferring energy from one point to another without transferring matter.

   2. What do waves transfer? 

      • Waves transfer energy, information, and momentum.

   3. What do waves NOT transfer?

      • Waves do not transfer mass or matter itself, only the energy associated with the wave.

2. Types of waves

   • Transverse waves: oscillate perpendicular to the direction of travel.

   • Longitudinal waves: oscillate parallel to the direction of travel.

   • Surface waves: a combination of transverse and longitudinal motions.

   • Properties of waves (amplitude, wavelength, crest, trough, frequency, etc)

Surface Waves

1. What type of motion do surface waves have? Hint: it’s not perpendicular as you would see in transverse waves.

   • Surface waves move in a circular motion, not perpendicular as seen in transverse waves.

Wave Energy

1. How is amplitude related to wave energy? (Proportionality) 

   • Amplitude is directly proportional to wave energy; higher amplitude indicates more energy transfer.

2. How is frequency related to wave energy? (Proportionality)

   • Frequency is also directly proportional to wave energy; higher frequency indicates more energy.

3. How do devices use waves to create energy?

   • Devices like turbines and generators utilize waves to convert wave energy into mechanical or electrical energy.

Waves in different media

1. Do seismic waves travel faster in more dense rocks or less dense rocks? Does the refracted wave move closer to 90 degrees (normal line) or does it move further away from 90 degrees (normal line) with the boundary?

   • Seismic waves travel faster in more dense rocks. When they cross a boundary, the refracted wave moves closer to 90 degrees (normal line) as it enters denser material.

2. Do sound waves travel faster in solid, liquid or gas? Does the refracted wave move closer to 90 degrees (normal line) or does it move further away from 90 degrees (normal line) with the boundary when it passes from air to liquid?

   • Sound waves travel fastest in solids, then liquids, and slowest in gases. When moving from air to liquid, the refracted wave moves closer to 90 degrees (normal line) as it enters the denser medium.

Properties of light 

1. Refraction, Reflection, absorption, diffraction, total internal reflection.

   • Light exhibits refraction, reflection, absorption, diffraction, and total internal reflection.

2. How does light react when it moves into mediums with different densities? If light moves from air to water, does the refracted ray move closer to the to 90 degrees (normal line) or does it move further away from 90 degrees (normal line) with the boundary? Does this mean it speeds up or slows down? 

   • When light transitions between different densities, such as from air to water, it bends toward the normal line, which indicates it slows down in a denser medium.

3. In terms of speed, what does it mean when the refracted wave is bent up or bent down?

   • When the refracted wave is bent upwards, it indicates that it speeds up; conversely, bending down indicates slowing down.

4. Can you locate and name the incident ray, angle of reflection, and angle of refraction on a diagram?

   • In diagrams, the incident ray is the incoming ray, the angle of reflection is equal to the angle of incidence, and the angle of refraction is found on the refracted ray.

5. How do fiber optics transfer messages? What properties of light do they take advantage of? Research the topic of “Total Internal Reflection”

   • Fiber optics use total internal reflection to transfer information by transmitting light through flexible glass or plastic fibers.

Electromagnetic Spectrum

1. What are the different forms of Electromagnetic waves?

   • Different forms include radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

2. What are some properties of these waves?

   • Properties include speed (all travel at light speed in a vacuum), wavelength, and frequency.

3. What types of EMR do cell phones use to transmit information?

   • Cell phones use microwaves and radio waves to transmit information.

Sound

1. What is needed for sound waves to move between objects?

   • Sound waves require a medium (solid, liquid, or gas) to transfer between objects.

2. What happens to sound in a vacuum? 

   • Sound cannot travel in a vacuum because there are no particles to transmit the sound.

3. What happens to sound as it travels between mediums with different densities? Hint: it’s different than light.

   • As sound travels through different densities, it can reflect, refract, and diffract, altering its speed and intensity, which differs from light behavior.

Analog Vs. Digital Signals

1. What are they? How are they similar? How are they different?

   • Analog signals are continuous waves, while digital signals are discrete and represented in binary form. Both transmit information but differ in representation and processing.

2. Which is more reliable?

   • Digital signals are generally more reliable due to their resistance to noise and degradation.

3. How are analog and digital waves represented?

   • Analog waves are represented by smooth waveforms; digital signals are represented by square waves (1s and 0s).

4. How does information travel using digital signals? 

   • Digital information travels by converting data into binary codes that are transmitted and processed by electronic devices.

Speed = frequency • wavelength

1. Can you perform simple calculations using this formula?

   • Yes, one can perform calculations using this formula to determine wave speed given frequency and wavelength, or vice versa.