A sound wave produced by a loudspeaker can travel through water, but not through a vacuum. In comparison, a red light wave produced by a laser can
travel through
A. both water and a vacuum
B. a vacuum, but not through water
C. neither water nor a vacuum
D. water, but not through a vacuum

Wo audio speakers are placed on a vertical rail. speaker a is placed at head-level while speaker b is place at some variable height, \delta yδy, above speaker a. both speakers receive simultaneous input from a sine-wave generator so the speakers each produce a pure sinusoidal sound wave with a wavelength of 0.531 meters. calculate the lowest height that speaker b can be placed above speaker a to produce a minimum of sound heard by person standing \delta x = 7.86δx=7.86 meters directly in front of speaker a.

If a simple machine reduces the strength of a force, what must be increased?

If an electric circuit is not grounded it is best to reach out and touch it to provide the ground a.true or b.false