Sound

Amplitude

Step 1: Loudness is the degree of sensation produced in our ears by sound waves. Step 2: Amplitude represents the maximum displacement of particles from their rest position during vibration. Step 3: Greater amplitude means particles move farther from their rest position, carrying more energy. Step 4: More energy reaching our ears creates a louder sensation, like striking a bell harder. Step 5: Frequency determines pitch, wavelength relates to frequency, and time period is the inverse of frequency, none of which directly affect loudness.

Solids

Step 1: Sound speed depends on how tightly packed the particles of the medium are. Step 2: In solids, particles are very closely packed and strongly bonded, allowing vibrations to transfer quickly. Step 3: In liquids, particles are less tightly packed than solids, so sound travels slower. Step 4: In gases, particles are far apart with weak bonds, making sound travel slowest among the three states. Step 5: Sound cannot travel through vacuum as there are no particles to vibrate and transmit the wave.

ν = 1/T

Step 1: Frequency is the number of complete oscillations per unit time (usually per second). Step 2: Time period is the time taken to complete one oscillation. Step 3: If one oscillation takes T seconds, then in 1 second there will be 1/T oscillations. Step 4: By definition, frequency = number of oscillations per second = 1/T. Step 5: This inverse relationship means high frequency corresponds to short time period and vice versa.

More than 0.1 seconds

Step 1: Our brain retains the sensation of sound for about 0.1 seconds (persistence of hearing). Step 2: If reflected sound returns within 0.1 seconds, it mixes with the original sound creating reverberation. Step 3: For a distinct echo, the reflected sound must arrive after 0.1 seconds when the original sound sensation has faded. Step 4: This time gap allows us to distinguish between the original sound and its reflection. Step 5: Less than 0.1 seconds produces reverberation, while exactly 0.1 seconds is the threshold boundary.