a sound wave has a frequency of 20 Hz and a wavelength of 100 m. what is the wave speed? a) 2000m/s b) 100m/s c)50 m/s d)0.20 m/s

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?

The energy produced as a result of this flow of electrons from atom to atom is called

Ain is , is 's of ? 0.62 0.79 1.27 1.50