Which contributes most to our average dose of background radiation? A) Natural sources
B) Artificial sources
C) Natural and artificial sources both contribute 50 per cent#

A150 w lamp emits light of wavelength 590 nm uniformly in all directions. what is the photon flux (photons per unit area per unit time) on a small screen at a distance 2.3 m from the lamp? assume the photons are uniformly distributed over the surface of a sphere of radius 2.3 m.

Around faucet handle is part of a(n) a. lever b. screw c. inclined plane d. wheel and axle

Aregion of space in which a measurable gravitational force is indicated by the force exerted on a test mass is called