The half life of carbon 14 is 5730 years. if an 8 gram sample of one carbon is as radioactive as 1 gram of a current sample then the age of the old sample is
a-1910 years
b-716 years
c-17190 years
d-none of the above

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.

Lightning is an example of what phenomenon? a release of a large amount of energy an absorption of a large amount of energy a natural electric circuit a natural electric current

Which describes an object in projectile motion? check all that apply. a.gravity acts to pull the object downb. the object moves in a straight path. c.the forward velocity of the object is 0 m/s. d.the object’s inertia carries it forward. e.the path of the object is curved.