Name: __________________________________Physical Science-Physics

Sound & Light Practice Test

This practice test is meant to be a tool to help you prepare for your Sound & Light assessment. While taking the practice test is a great start, you should also review your note packets, labs, and homework.

Below are the equations you will need for this practice test

Vocabulary/Concepts to understand: Mechanical vs. Electromagnetic waves

Compressional vs. Transverse waves

Wavelength

Amplitude

Crest/Trough

Compression/Rarefaction

Constructive Interference

Destructive Interference

Resonance

Intensity/Loudness

Pitch/Frequency

Transmission, Reflection, Absorption

Refraction

Reflection—Regular & Diffuse

Velocity (v) = frequency (f) x wavelength () f = v/ = v/f

Frequency = # of wavelengths / time

Wave Properties1. Use the following vocabulary words to label the waves below:

a. Transverse, compressional, wavelength, amplitude, crest, trough, compression, rarefaction

2. How are sound and light waves different? Make sure to use specific vocabulary!

3. The matter that is in space is very spread out across vast distances. Knowing this, why are mechanical waves useless in outer space? How does this relate to why we cannot hear things in space?

4. Describe the relationship between frequency and wavelength.

Sound Waves & Relationships5. A student plays two tuning forks. Tuning fork A has a frequency of 350Hz and tuning fork B has a frequency of

124Hz. a. Which tuning fork will produce a wave the shortest wavelength? Explain your answer.

b. Which tuning fork with produce a note with the highest pitch? Explain your answer.

6. To the right is a diagram of two waves being added together. a. Does this represent constructive or destructive interference? Explain your

answer using physics concepts.

b. How would this interference affect the loudness (intensity) of the sound wave? Explain why by referencing the “anatomy” of the resulting sound wave.

7. Herds of African elephants are generally spread over large areas. Infrasonic sound waves (sound waves below the human range of frequency detection) are used by these elephants to locate each other and to communicate. Scientists have detected sound waves with frequencies as low as 13 Hz being produced by elephants. Assuming a speed of sound of 350 m/s, determine the wavelength of these sounds waves.

8. The velocity of a sound wave is 320m/s. The distance between two wave crests is 0.45m. What is the wave frequency?

9. Marine organisms, like dolphins, use sound waves to communicate through water. Dolphins can sense frequencies as high as 160,000Hz. These sound waves have a wavelength of 0.009 m. Given this information, calculate the velocity of these sound waves in water.

10. A violin plays a note that produces a sound wave in which 97 wavelengths travel by a fixed point in 2.3 seconds. What is the frequency of this note?

11. A student conducts the speed of sound lab that we did in class. She uses a tube and tuning fork to create resonance within an air column. The student finds that a tuning fork with a frequency of 324Hz produces a wavelength of 1.1m . What is the speed of sound in the lab she is working in?

a. If this student conducted this experiment outside on a cold day, how would the speed of sound change? Explain your answer.

Light Waves & Properties

12. Below is a picture of three candle holders made of different materials. Below each picture, label whether the objects are transmitting, reflecting, or absorbing light (Hint: there might be more than one answer for each)

13. What is refraction?

14. In the diagram below, which image represents refraction and which represents reflection? Explain the difference between these two properties of light.

15. Most objects reflect light. Explain why only some objects (mirrors) can produce perfect reflections.

16. Which color of light has the longest wavelength? Which color has the shortest wavelength?

17. White light is a mixture of all the colors of light. Explain how the properties of wavelength and refraction allow colors of light to be separated through a prism.