The atmosphere extends up to an altitude of about

330 miles
200 miles
200 km
50 miles

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.

An object resting on a table weighs 100 n. with what force is the object pushing on the table? with what force is the table pushing on the object? explain how you got your answer.

Frequency of electromagnetic waves that a radio station is assigned. what do you call this type of wave?