Chapter 7 introduces the concepts of gravity and energy. In the first part of the chapter, you will learn that gravity, the force that causes an apple to fall from a tree, also keeps planets orbiting ...Chapter 7 introduces the concepts of gravity and energy. In the first part of the chapter, you will learn that gravity, the force that causes an apple to fall from a tree, also keeps planets orbiting the Sun, and is present throughout the Universe. You will explore properties of surface gravity on other planets and the orbits of planets, stars, or any object in space. The second part of the chapter focuses on the many forms of energy, especially gravitational potential energy and kinetic energy.
