1.
Special dog whistles make sounds that people cannot hear, no matter how hard you blow the whistle. Why can't people hear these whistles?
Correct Answer
A. The pitch is too high.
Explanation
Special dog whistles make sounds that people cannot hear because the pitch is too high. Human hearing has a limited range, typically between 20 Hz and 20,000 Hz. Dog whistles are designed to produce frequencies above this range, allowing them to be audible to dogs but not to humans. This high-pitched sound is outside the human hearing threshold, making it impossible for people to perceive the whistle's sound, regardless of how hard it is blown or any other factors such as volume or size.
2.
A string telephone is made by stretching a piece of strings between two cups. how does the string telephone work?
Correct Answer
B. Sounds make the string vibrate.
Explanation
The string telephone works by transmitting sounds through vibrations. When someone speaks into one cup, the sound waves travel through the air and reach the string. The string then vibrates, carrying the sound waves to the other cup, where they are heard by the person on the other end. This method of transmitting sound through vibrations is the basic principle behind how a string telephone works.
3.
Sam was swimming underwater when she thought she heard a porpoise squeak. What can be said about Sam's observation?
Correct Answer
D. Water particles vibrated against her eardrum, which caused her to hear the porpoise.
Explanation
Sam's observation can be explained by the fact that water particles vibrated against her eardrum, which caused her to hear the porpoise. This is because sound can travel through water and reach our ears, contrary to the statement that sound cannot travel in water.
4.
Which of these causes sound?
Correct Answer
B. Something vibrating
Explanation
Vibrations are responsible for producing sound. When an object vibrates, it creates waves of pressure in the surrounding medium, such as air, which our ears perceive as sound. Therefore, something vibrating is the cause of sound.
5.
Through which will sound travel fastest?
Correct Answer
D. Wood
Explanation
Sound travels fastest through solids because the particles in solids are closely packed together, allowing for faster transmission of sound waves. In the case of wood, the molecules are tightly bound, enabling sound to travel quickly through its structure.
6.
You stretch a rubber band and pull on one side. The rubber band makes a sound. You stretch the same rubber band even more and pull on it again. It makes a different sound. What property of sound changes?
Correct Answer
B. Pitch
Explanation
When you stretch the rubber band even more and pull on it again, the pitch of the sound it produces changes. Pitch is a property of sound that refers to how high or low a sound is perceived. So, by stretching the rubber band further, the tension in the band increases, causing it to vibrate at a higher frequency and produce a higher pitch sound.
7.
Which term means how loud a sound it?
Correct Answer
D. Volume
Explanation
Volume is the term that refers to how loud a sound is. It is a measure of the intensity or amplitude of a sound wave. The greater the amplitude of a sound wave, the louder the sound is perceived to be. Therefore, volume is the correct term to describe the loudness of a sound.
8.
What must change in order for the pitch of a sound to change?
Correct Answer
A. Frequency
Explanation
The pitch of a sound is determined by its frequency, which refers to the number of vibrations or cycles per second. When the frequency of a sound wave changes, the pitch of the sound also changes. Therefore, in order for the pitch of a sound to change, the frequency of the sound wave must change.