Newton initially calculated the speed of sound using an isothermal model, which yielded approximately 281 m/s. This value was lower than the experimental value because he did not account for the adiabatic nature of sound propagation in air, which was later corrected by Laplace.

At 25°C, the speed of sound in air is approximately 346 m/s, and in distilled water, it is approximately 1498 m/s. Both values are standard physical constants used in acoustics for these specific temperatures and conditions, confirming that both statements provided are scientifically accurate.

The speed of sound in seawater varies based on temperature, salinity, and pressure. At standard conditions (approximately 20°C and typical salinity), the speed of sound is widely accepted to be around 1531 m/s. This value is a standard reference point in underwater acoustics and oceanography.

Reflection of sound occurs when sound waves encounter an obstacle or a boundary between two media and are redirected back into the medium from which they originated. This principle is the basis for echoes and reverberation in enclosed spaces, following the law of reflection where the angle of incidence equals the angle of reflection.

The speed of sound depends on the medium's elasticity and density. Sound travels fastest in solids because the particles are more closely packed and the material has a higher elastic modulus compared to liquids or gases, allowing for faster transmission of mechanical vibrations.

Pitch is the human perception of the frequency of a sound wave. A higher frequency corresponds to a higher pitch (a sharper sound), while a lower frequency corresponds to a lower pitch (a deeper sound). Amplitude, conversely, is related to the loudness of the sound.

Pitch is the subjective perception of the frequency of a sound wave. A higher frequency corresponds to a higher pitch, while a lower frequency corresponds to a lower pitch. Amplitude, conversely, is related to the loudness or intensity of the sound, not its pitch.

Loudness is a subjective perception related to the intensity of sound, which is determined by the amplitude of the vibration. As the amplitude of the vibrating source increases, the energy transferred to the medium increases, resulting in a higher intensity and a louder sound perceived by the human ear.

Sound waves are mechanical waves that require a material medium (solid, liquid, or gas) to travel because they propagate through the vibration of particles. A vacuum contains no particles, therefore sound cannot travel through it.

The human ear has a persistence of hearing of approximately 0.1 seconds. For an echo to be heard distinctly, the reflected sound must reach the ear at least 0.1 seconds after the original sound. Given the speed of sound is about 344 m/s, the total distance traveled is 34.4 m, meaning the obstacle must be at least 17.2 m away.