Question

When you lift a book from the ground to your desk, what kind of work do you do, negative or positive? By lifting the book, what do you change? Does the book gain or lose energy? What kind of energy?

Answer 1

When you lift a book from the ground to your desk it would be called potential energy. If a book weighs 15 Newtons (N) then it takes a force of 15 Newtons (N) to pick it up. In other words it would be positive work. When you move the book you are giving it energy. The energy will turn into kinetic if you put the book back down. You would be changing it’s position and it’s energy.

Answer 2

Answer: You do negative work, since you're using your strength. When lifting the book, your muscles contract. When you lift the book, it gains energy.

Energy: Gravitational Potential Energy

Step-by-step explanation: