Your sentence "My backpack stubbornly refuses all attempts to lift it even when I use both hands" contains personification. This is because it attributes the human characteristic of being "stubborn" to an inanimate object, implying that the backpack has a will of its own.
Here are examples of the other literary devices you mentioned:
- Simile: "My backpack feels as heavy as a mountain."
- Hyperbole: "It weighs a ton!"
- Onomatopoeia: "The zippers went zip and the buckles clicked as I struggled to lift it."
Feel free to ask if you need further assistance!