1.
What is sound?
Correct Answer
B. A form of energy
Explanation
Sound is a form of energy because it is produced by the vibration of particles in a medium, such as air or water. These vibrations create waves that travel through the medium and are detected by our ears as sound. Energy is transferred from the vibrating source to the surrounding particles, causing them to vibrate and carry the sound waves. Therefore, sound is not just a form of loudness, movement, or noise, but rather a form of energy that can be measured and quantified.
2.
What causes sound?
Correct Answer
C. The vibration of an object
Explanation
Sound is caused by the vibration of an object. When an object vibrates, it creates waves of pressure in the surrounding medium, usually air. These waves travel through the air as sound waves, which our ears detect and interpret as sound. The vibration of the object disturbs the air particles, causing them to move back and forth, creating areas of compression and rarefaction. This movement of particles transfers the energy of the vibration, allowing sound to propagate through the medium. Therefore, the correct answer is "the vibration of an object."
3.
What unit is used to measure the volume of a sound?
Correct Answer
A. The decibel
Explanation
The correct answer is the decibel. The decibel is a unit used to measure the intensity or loudness of sound. It is a logarithmic scale that compares the sound pressure level to a reference level. The decibel scale allows for the measurement of a wide range of sound levels, from the faintest whispers to the loudest sounds. It is commonly used in fields such as physics, engineering, and audio technology to quantify and compare sound levels.
4.
What level of sound will cause immediate damage to the human ear?
Correct Answer
B. 140 dB
Explanation
Exposure to sound levels above 140 dB can cause immediate damage to the human ear. Sound at this level is extremely loud and can lead to permanent hearing loss, as well as other negative effects such as pain, ringing in the ears (tinnitus), and even physical damage to the ear structures. It is important to protect our ears from excessive noise to maintain good hearing health.
5.
What happens to the wavelength of a sound when the frequency increases?
Correct Answer
A. It decreases
Explanation
When the frequency of a sound increases, the wavelength decreases. This is because frequency and wavelength are inversely proportional to each other. As the frequency increases, the number of waves per second increases, causing the distance between each wave (wavelength) to decrease. Therefore, the correct answer is that the wavelength of a sound decreases when the frequency increases.
6.
Sound travels faster through a solid than through a gas.
Correct Answer
A. True
Explanation
Sound travels faster through a solid than through a gas because the particles in a solid are closer together, allowing sound waves to propagate more quickly. In a gas, the particles are more spread out, resulting in a slower transmission of sound.
7.
What type of waves are sound waves?
Correct Answer
C. Compressional waves
Explanation
Sound waves are a type of compressional waves. Compressional waves are characterized by the particles of the medium vibrating parallel to the direction of wave propagation. In the case of sound waves, they are produced by the vibration of particles in a medium, such as air or water. These vibrations create areas of compression and rarefaction, resulting in the transmission of sound energy. Therefore, compressional waves accurately describe the nature of sound waves.
8.
Sound waves move
Correct Answer
D. In all directions away from the source
Explanation
Sound waves are mechanical waves that require a medium, such as air or water, to travel through. When a sound is produced, it creates a disturbance in the medium, causing particles to vibrate. These vibrations then propagate in all directions away from the source, creating a pattern of compressions and rarefactions. This is why we are able to hear sound from different directions, as the waves spread outwards in all directions from the source. Therefore, the correct answer is "in all directions away from the source."
9.
Sound must have _____ to move through.
Correct Answer
B. Matter
Explanation
Sound is a mechanical wave that requires a medium to propagate through. This medium can be a solid, liquid, or gas, which are all forms of matter. Therefore, sound must have matter to move through in order to transmit its vibrations and be heard.
10.
Sounds carry
Correct Answer
A. Energy
Explanation
Sounds carry energy as they are produced by the vibration of molecules or particles in a medium. This vibration causes the molecules or particles to transfer their energy to neighboring molecules or particles, creating a wave of energy that propagates through the medium. Therefore, the correct answer is energy.