Which isotope for copper is more common on earth? which is more common in rocks? (choices are copper 65 or copper 63)

You carry a 7.0-kg bag of groceries 1.2 m above the ground at constant speed across a 2.7m room. how much work do you do on the bag in the process? (a) 157j (b) 0.00j (c) 185j (d) 82j

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 .

Two masses are connected by a rope that hangs over a pulley as shown below. the pulley is a uniform cylinder of radius 푅=0.381meters and mass 푀=3.1푘푔. initially 푚"is on the ground and 푚#rests 2.5 meters above the ground. if the system is released, use conservation of energy to determine the speed of 푚#just before it strikes the ground. assume the pulley bearing is frictionless.