Final answer:
The question pertains to calculating the energy in joules that impacts an eardrum when exposed to a 90.0 dB sound over a certain period, as well as the power input needed for a speaker to produce a specific sound intensity level, all of which fall under the study of sound intensity in physics.
Step-by-step explanation:
The question involves the application of sound intensity and energy concepts, which are an integral part of the physics curriculum. To calculate the energy that falls on an eardrum exposed to a sound of a certain intensity level over a given period, we need to consider the area of the eardrum and the time of exposure. For instance, an 8-hour exposure to a sound intensity level of 90.0 dB (decibels) could potentially cause hearing damage. The energy, in joules, striking the 0.800-cm-diameter eardrum can be found by converting the decibel level to intensity in watts per meter squared, then using the formula E = I × A × t, where E is energy in joules, I is intensity in watts per meter squared, A is the area of the eardrum in meters squared, and t is the time in seconds.
Loudspeakers can create a high sound intensity level such as 90.0 dB with relatively low power input due to the amplifier's efficiency, even if it is as low as 1.00%. When discussing the amount of power needed for a loudspeaker to achieve a certain sound intensity level, we must consider the speaker's diameter and the efficiency of the speaker.
Understanding how the human ear perceives sound is also crucial in physics. Our ear can differentiate sounds arriving just 1.00 ms apart, which allows us to calculate the minimum distance between two sound sources based on the speed of sound and the time difference of arrival of the sounds to the ear.