Two identical masses are moving down a slope. one mass is traveling twice as fast as the other mass. how does the kinetic energy of one mass compare to the other?

What is hidden during a lunar eclipse? isn't the moon hidden?

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?

Alfred pushes on a heavy box, but cannot move it. the box has a lot of inertia motion friction gravity