Does the speed of the object affect friction? So which one would increase friction, going slowly, or going fast.
If possible an explanation? Thanks a bunch. :D

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?

Which type of basaltic lava flow has a fairly smooth

Describe how the motion of a spring being pushed forward and backward is similar to the motion of air particles in a sound wave.