How are sounds made? A. The sound source causes energy around the ear to compress. B. The sound source causes air particles to circle. C. The sound source causes a chain reaction of vibrations. D. The sound source causes air to be forced into the ear.

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?

More solar radiation is absorbed by earth’s surface than by

What happens when you slowly pulled the carboard?