The earth rotates once around it spin axis in 23 h 56 min. If the radius of the earth is 6.4 X 10^6 m, calculate the speed of a person sitting at the equator

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?

When the magnetic domains in a material can be aligned, but eventually drift out of alignment, the material is

Convection occurs when thermal energy is transferred by the movement of