A point charge of +Q= 6.3 μC is placed at the center of an equilateral triangle. Two additional charges of +Q are placed at two of the triangles vertices such that the radius from each of the charges to the center is 0.19m. What is the magnitude of the net electrostatic force acting on the charge in the center of the triangle?

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.

Critical mass is the of material required to produce a chain reaction. a.) minimum amount b.) atomic mass c.) precise amount d.) maximum amount

Select all the correct answers. which changes will increase the rate of reaction during combustion? decreasing the area of contact between the reactants adding more oxygen to the reaction removing heat from the reaction changing the reactants from solid form to powdered form lowering the exposure of the reactants to air