How is a pitch that is heard when waves are closely spaced together described? A. the same as when waves are spaced far apart

B. high

C. low

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.

Work out sian speed for the first 30 minutes of her journey. give your answer in km/h.

Write down two additional questions about earth's magnetic field that will make your presentation more informative.