order to assess whether viewpoints on decriminalization of marijuana for medical purposes change with age, four groups of participants, ages 20, 30, 40, and 50, are asked whether they support this issue. What is one flaw of this design?

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.

Aplane travels 1000 miles in 5 hours .what is the planes average speed?

How does an observation about an object differ from an inference about that object