Physical Science Module 14

Supersonic speed refers to any speed that exceeds the speed of sound in a particular substance. This means that if an object is traveling faster than the speed of sound in air, for example, it is considered to be traveling at supersonic speed. Therefore, the given statement is true as it accurately defines supersonic speed as any speed faster than the speed of sound in the substance of interest.

When an object travels at or above the speed of sound, it creates a shockwave that produces a loud and distinctive sound known as a sonic boom. This occurs because the object is moving faster than the speed at which sound waves can propagate, causing the waves to pile up and create a sudden change in pressure. The resulting sound is often described as a loud boom or explosion-like noise. Therefore, the correct answer is Sonic Boom.

When the pitch of a sound increases, it indicates that the source of the sound is approaching the listener. In this scenario, as the person is driving and the pitch of the siren keeps getting higher, it suggests that they are driving towards the siren.

A wave with a direction of propagation that is parallel to its direction of oscillation is called a longitudinal wave. In a longitudinal wave, the particles of the medium move back and forth in the same direction as the wave is traveling. This type of wave is characterized by compressions and rarefactions, where the particles are pushed together and spread apart, respectively. Sound waves are examples of longitudinal waves, as the air particles vibrate parallel to the direction of the sound wave.

This is a true statement because space is a vacuum, meaning it is mostly empty and devoid of air or any other medium that sound waves require to travel. In the absence of air molecules, there is no medium for sound waves to propagate through, resulting in no sound being transmitted. Therefore, even if someone were to scream in space, there would be no air molecules to vibrate and carry the sound waves, making it impossible for anyone to hear the scream.

Sound waves are longitudinal waves, which means that the particles of the medium vibrate parallel to the direction in which the wave travels. In other words, the oscillations of the sound wave occur in the same direction as the wave propagation. This is why the correct answer is "Parallel."

The man's sound waves have lower frequencies than those of the woman. This is because the man is singing the low notes, which correspond to lower frequencies. The woman, on the other hand, is singing the high notes, which correspond to higher frequencies.

A wave with a direction of propagation that is perpendicular to its direction of oscillation is called a transverse wave. In a transverse wave, the particles of the medium vibrate up and down or side to side, while the wave itself moves forward in a perpendicular direction. This type of wave is commonly observed in electromagnetic waves, such as light waves, where the electric and magnetic fields oscillate perpendicular to the direction of wave propagation.

Pitch refers to the perceived highness or lowness of a sound. It is primarily determined by the frequency of the sound wave, with higher frequencies corresponding to higher pitches and lower frequencies corresponding to lower pitches. Wavelength, on the other hand, refers to the distance between two corresponding points on a sound wave and is not directly related to pitch. Frequency, as mentioned earlier, is the number of cycles of a sound wave that occur in one second and is directly related to pitch.

Sound waves travel faster in water than in air because water is denser than air. The denser the medium, the faster sound waves can travel through it. Therefore, when sound waves hit the water after traveling through the air, they will continue to travel faster in the water.

The speed of sound in air is affected by temperature. As the temperature increases, the speed of sound also increases. At a temperature of 25 degrees Celsius, the speed of sound in air is approximately 346.5 m/sec.

The wavelength of a sound wave is inversely proportional to its frequency. Since the woman is singing the high notes, her sound waves have a higher frequency and therefore shorter wavelengths. On the other hand, the man is singing the low notes, so his sound waves have a lower frequency and longer wavelengths. Therefore, the wavelengths of the man's sound waves are longer than those of the woman.

The longer recorder is capable of playing notes with the lowest pitch because the length of the instrument affects the wavelength of the sound produced. In general, longer instruments produce lower-pitched sounds because the longer wavelength corresponds to a lower frequency. Therefore, the second recorder, being significantly longer, will be able to produce notes with a lower pitch compared to the shorter first recorder.

Infrasonic waves have the longest wavelength compared to sonic and ultrasonic waves. Infrasonic waves are sound waves with frequencies below the range of human hearing, typically below 20 Hz. Due to their low frequency, they have a longer wavelength. Sonic waves, on the other hand, are sound waves that fall within the range of human hearing, typically between 20 Hz and 20,000 Hz. Ultrasonic waves have frequencies above the range of human hearing, typically above 20,000 Hz, and therefore have shorter wavelengths compared to infrasonic waves.

The speed of sound in air at 10 degrees Celsius is approximately 343 meters per second. Mach 3 is three times the speed of sound, so the jet is traveling at 3 * 343 = 1029 meters per second. Therefore, the closest option is 1012.5 m/sec.

The frequency of a sound wave is determined by the speed of sound in the medium and the wavelength of the wave. In this case, the wavelength is given as 2 meters. The speed of sound in air at 17 degrees Celsius is approximately 343 meters per second. To find the frequency, we can use the formula: frequency = speed of sound / wavelength. Plugging in the values, we get: frequency = 343 m/s / 2 m = 171.5 Hz. Rounding to the nearest hundredth, the frequency is approximately 170.85 Hz.

The decibel scale is logarithmic, meaning that a 10 decibel increase represents a tenfold increase in sound intensity. Since the sound is amplified from 30 decibels to 80 decibels, there is a 50 decibel increase, which corresponds to a 10^5 or 100,000 times increase in sound intensity.

Since the woman is singing the high notes, which have a higher frequency, the amplitude of her waves would be smaller compared to the man's waves. This is because higher frequency waves have shorter wavelengths and therefore smaller amplitudes.

The speed of sound waves is the same as the woman's voice. The speed of sound is determined by the medium through which it travels, such as air, and is not affected by the pitch or volume of the sound. Therefore, regardless of whether the woman is singing high or low notes, the speed of the sound waves she produces will remain constant.

The speed of sound in air is approximately 343 meters per second. Since we hear the thunder 2 seconds after seeing the lightning strike, it means that the sound traveled for 2 seconds at a speed of 343 meters per second. Therefore, the distance the sound traveled is 2 seconds multiplied by 343 meters per second, which equals 686 meters. However, since we want to know the distance to the lightning strike, we need to divide this distance by 2, resulting in 343 meters. Therefore, the lightning strike was approximately 675 meters away.