Читать книгу Physics I For Dummies - Steven Holzner - Страница 46

Motion that takes place in the world isn’t always in one dimension. Motion can take place in two or three dimensions. And if you want to examine motion in two dimensions, you need two intersecting meter sticks (or number lines), called axes. You have a horizontal axis (the x-axis) and a vertical axis (the y-axis). (For three-dimensional problems, watch for a third axis (the z-axis) sticking straight up out of the paper.)