Waves and Their Properties Quiz

Waves and Their Properties

• Waves are propagating dynamic disturbances that travel between vibrating and oscillating fields.
• Waves contain crests (upper points) and troughs (lower points).
• Waves can exhibit different behaviors depending on how they travel and propagate.
• Examples include surface water waves, light, sound, and specific types of motion.

Sound

• Sound is vibrations traveling through air or other mediums.
• Humans and animals can hear sound when it reaches their ears.
• Sound is produced when matter vibrates within a medium.
• Sound waves travel in a direction parallel to the source's path.

Longitudinal Waves

• Longitudinal waves travel in a direction parallel to the material's action.
• They consist of compressions (closer particles, decrease in volume) and rarefactions (particles spread out, increase in volume).

Properties: Longitudinal Waves

• Wavelength (λ): distance between two successive compressions.
• Frequency (f): number of compressions passing through a point per second.
• Period (T): time taken for one full vibration.

Properties of Sound

• Pitch: perception of sound frequency by the human ear. Higher pitch means higher frequency, lower pitch means lower frequency.
• Loudness: perception of sound wave amplitude. Amplitude is a measure of the maximum disturbance of sound. Amplitude can also be described as the height of a crest/trough in relation to the wavefront.

Light

• Light is radiation traveling through a medium (or a vacuum).
• Light allows objects to be visible.
• Light consists of waves that can travel through a vacuum.
• Light propagates through oscillating electric and magnetic fields at perpendicular directions.

Transverse Waves

• Transverse waves travel in a direction perpendicular to the material's action.
• Transverse waves contain crests (high points) and troughs (low points).
• Crests are treated like compressions, and troughs like rarefactions.

Properties: Transverse Waves

• Wavelength: distance between two successive crests or troughs.
• Frequency: number of full waves that pass through a point in a second.
• Period: time taken for one full vibration.

Speed of a Wave

• Waves travel at different speeds based on their wavelengths (λ) and frequencies (f).
• Speed (v) = wavelength (λ) x frequency (f) (v = λf)
• Period (T) = 1 / frequency (f) (T = 1/f)

Wave Speed Calculations

• Example calculation 1: A wave with 32.75 Hz frequency and 12.50m wavelength has a speed of 409.38 m/s.
• Example calculation 2: A sound wave traveling at 331.45 m/s and 17.25 Hz frequency has a wavelength of 19.21 meters.
• Example calculation 3: A wave traveling at 85.64 m/s and 972 cm (9.72 m) length has a frequency of 8.81 Hz.
• Example calculation 4: A wave traveling at 67.65 m/s and 1385 dm (138.5 m) length has a period of 2.05 seconds.

Mechanical Waves

• Mechanical waves travel through different mediums, but cannot travel through a vacuum.
• Sound waves are mechanical waves needing a solid, liquid, or gas medium to travel.
• Sound waves travel fastest in solids, slowest in gases.
• Sound travels faster in higher temperatures.

Light as a Wave

• Light waves propagate through interchanging electric and magnetic fields rather than matter oscillations.
• Electric and magnetic fields exist in planes even without a medium.
• Light can travel through a vacuum.

Electromagnetic Waves

• Electromagnetic waves propagate in the presence or absence of a medium.
• Visible light is an electromagnetic wave that travels through a vacuum at 299,792,458 m/s (3x10⁸ m/s).
• The speed of light waves decreases as they enter a denser medium.
• When light travels through different media the speed changes, this is called refraction.

Refraction

• Refraction is a change in speed when waves pass through different optical densities.
• In refraction diagrams the incident angle (α), the angle at which light strikes an object or medium with respect to the normal line, and the refracted angle (β), the angle formed after light bends due to the change in optical density, are shown.

Colors of Light

• Visible colors of light each have their own refractive index.
• When white light passes through a prism it separates into various component colors.
• Colors have different speeds and corresponding wavelengths.

Frequency and Wavelength

• Red light has the longest wavelength and lowest frequency.
• Violet light has the shortest wavelength and highest frequency.
• Wavelength and frequency have an inverse relationship.

Short Quiz Questions and Answers

• Question 1: Wave (B).
• Question 2: Crest (A).
• Question 3: Longitudinal (D).
• Question 4: Trough (B).
• Question 5: Transverse (C).
• Question 6: Vacuum (D).
• Question 7: Mechanical (A).
• Question 8: Sound (B).
• Question 9: Frequency (C).
• Question 10: Amplitude (A).
• Question 11: Frequency (C).
• Question 12: Wavelength (B).
• Question 13: Refraction (C).
• Question 14: Incident (A).
• Question 15: Inversely Related (B).

Part II: Arrangement

• Arrange colors of light with respect to highest to lowest frequency.
• Arrange colors of light with respect to longest to shortest wavelength.

Part III: Solve It

• A radio wave traveling through a vacuum with a 1.5 kHz frequency has a wavelength of approximately 200,000 meters.