Which method of separation would work on a homogeneous mixture salt water

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.

In a given chemical reaction, the energy of the products is greater than the energy of the reactants. which statement is true for this reaction?

Using the free-body diagram, calculate the net force acting on the sled. is the sled in a state of dynamic equilibrium?