What is the potential energy of a 2kg hammer which is 0.4 meter up

Why is there friction between objects

Disney, viacom and aol time warner are examples of

Wave functions describe orbitals in a hydrogen atom. each function is characterized by 3 quantum numbers: n, l, and ml. if the value of n = 2: the quantum number l can have values from to . the total number of orbitals possible at the n = 2 energy level is .