You are correct! The first statement, “There is a metric ton of books in my backpack,” is indeed an example of hyperbole, which is an exaggerated statement not meant to be taken literally. It emphasizes the heaviness or abundance of books in the backpack.
The second statement, “My backpack stubbornly refuses all attempts to lift it, even when I use both hands,” is an example of personification, as it attributes human qualities (stubbornness and refusal) to an inanimate object (the backpack). This technique adds depth to the description and emphasizes the difficulty of the situation.