Two sound waves are moving towards each other. A region of rarefaction overlaps with a region of rarefaction. Which of the following choices correctly describes the behavior of sound waves when they overlap as described? A. Constructive interference; the amplitude increases but the volume remains the same.
B. Constructive interference; the amplitude increases but the volume remains the same.

According to social exchange theory, altruistic behaviors benefit the individual who performs them.

Suppose that an electromagnetic wave which is linearly polarized along the x−axis is propagating in vacuum along the z−axis. the wave is incident on a conductor which is placed at z > 0 region of the space. the conductor has conductivity σ, magnetic permeability µ and electric permittivity ε. (a) find the characteristic time for the free charge density which dissipates at the conductor. (b) write the maxwell equations and derive the wave equation for a plane wave propagating in a conductor. (c) find the attenuation distance at which the incident amplitude reduces to e ^−1 of its initial value. (d) find the electric and magnetic fields inside the conductor. 8 (e) find the power loss per area of the incident electromagnetic wave at the surface of conductor.

Two polarizers are oriented at 70∘∘ to one another. unpolarized light falls on them. what fraction of the light intensity is transmitted?