The hodograph is a plot of velocity of the body on the x-y plane. The velocity vector of the body is drawn to scale such that its starting point is the origin. To illustrate the definition of hodograph, we take the case of a projectile projected under influence of gravity. Initially, the particle is moving at an angle θ to the horizontal with a velocity ${\overrightarrow{\mathrm{v}}}_0$ as shown. As time passes, its velocity changes under the influence of constant acceleration $\overrightarrow{\mathrm{g}}$. By equation of motion, we can say $\overrightarrow{\mathrm{v}}={\overrightarrow{\mathrm{v}}}_0+\overrightarrow{\mathrm{g}}\mathrm{t}$. Note that $\overrightarrow{\mathrm{g}}\mathrm{t}$ is always vertically downward. Here this velocity vector is drawn at 3 successive seconds. At the end of 3 seconds the velocity vector in this case becomes horizontal. This means that the body has reached the highest point. The trajectory is more difficult to work with because it is parabolic in shape.