In the following uniform motions in three dimensions are considered. To describe these motions a coordinate system is chosen whose x-axis is parallel to the earths surface and whose z-axis is directed upward. For simplification all motions have to take place in the x-z-plane. Consider a car driving straight ahead.. Give an example for the velocity = (v,y,z). Specify the components of the vector by separating them by commas. 4