Acertain siren radiates sound uniformly in all directions. at a distance of 17 m from the siren, the intensity level is 49 db. how many watts of power does this siren put out? the threshold of human hearing is 1.0 × 10-12 w/m2.

Which accurately compares concave and convex lenses?

This is one type of line graph in which the independent variable is time plotted on the x axis and the dependent variable, also numerical, is plotted on the y axis.

Aspectroscope breaks light up into its colors, allowing scientists to analyze light from the solar system and universe. by studying the spectral line patterns, widths, strengths and positions, scientists can determine the speed, position, and of celestial bodies. a) age b) origin c) rotation d) temperature