Why is earth's surface not riddled with craters as is that of the moon?

Abearing is designed to a reduce friction b. support a load c.guide moving parts such as wheels, shafts and pivots d. all of the above

Dao makes a table to identify the variables used in the equations for centripetal acceleration. what quantities belong in cells x and y?

Exercise 2. find the wavelength of a photon emitted when an electron jumps from the n = 3 energy level down to the n = 2 energy level. where is this photon in the electromagnetic spectrum?