Answer
Speed of the book will increase
Work Step by Step
İf we give the book any speed ( doesn't matter upward or downward it will have initial kinetic energy) so the total energy will be greater than there when there is no initial speed so when book reaches the student potential energy will be the same ( because height of student and building doesn't change) so only kinetic energy will change and because the total energy is greater than before and potential energy doesn't change book will have more kinetic energy and so more speed
