Aradioactive isotope of potassium has a half-life of 20 minutes if a 40 g sample of this isotope is allowed to decay for 80 minutes how many grams of the r adioactive isotope will remain

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.

Your science teacher brings in a speaker to talk to your class about climate change. during the session, students ask a few questions. which questions are related to the current evidence on climate change

Explain how a step-down transformer makes electricity safe for use in homes