Suppose the student does 25 joules of work lifting the book. Does the book lifted at constant speed gain potential energy, kinetic energy, or both? Explain. Is the potential energy gained by the book greater than, less than, or equal to 25 joules? Explain.

Ahanging spring stretches by 35.0 cm when an object of mass 450 g is hung on it at rest. in this situation, we define its position as x = 0. the object is pulled down an additional 18.0 cm and released from rest to oscillate without friction. what is its position x at a moment 84.4 s later? express your answer in cm.