1. A Comet orbiting around the Sun has a very eccentric orbit. The Semi-major axis of this Comet around the Sun is 19.6 A. U. and the focal length is 18.0 A. U. What
is the eccentricity of the Comet?

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.

Jenny wants to test the electrical conductivity of two substances dissolved in water. she is preparing the containers for the experiment. which factor is most important for her to control? a) volumes of the solutions b) appearance of the solutions c) temperatures of the solutions d) concentrations of the solutions

Which radioisotope is used in dating geological formations?