1. A book sitting on a shelf has a potential energy of 9800 J and is sitting at a height of 10 m. What is the book’s mass?

Which contributions did galileo make to the model of the solar system? check all that apply. a mathematical model for the orbits of the planets scientifically accurate data on planetary orbits data that showed that planets reflected sunlight similar to earth's moon up the idea that stars are other suns that do not move u observations of the moons of jupiter rotating around the gas giant