A 6.86 N book is moved to 3 different shelves on a bookcase. The book moved from a height 1.0 m to 1.5 m and then finally to 3.0 m. What is the book's mass (kg) and potential energy (J) at each of the positions on the shelf?

To protect all four receptacles on a branch circuit that surrounds a swimming pool, you would install which of the following configurations? a. gfci feed-through receptacle at the end of the load's circuit b. gfci-terminated receptacle at the beginning of the load's circuit c. gfci feed-through receptacle at the beginning of the load's circuit and the other receptacles connected to the load side of that receptacle d. gfci-terminated receptacle at each end of the load's circuit

Idon’t quite understand this problem

Explain earth's motion, using the terms "precession" and "rotation" in your answer.