In physics, there are two types of velocity: vertical and horizontal. Vertical velocity is used only when an angle of trajectory is involved. Horizontal velocity is measured when something is moving along a horizontal trajectory. Like speed, horizontal velocity is measured in meters per second. The formula for finding horizontal velocity is velocity equals horizontal displacement at time divided by time. Displacement is the distance something has travelled from a point of origin in a set amount of time.
Write the horizontal velocity problem as V = Δx / t. For example, V = 20 metres / 5 seconds. The delta (Δ) symbol means "change in," in this case referring to a change in horizontal position (x).
Divide the horizontal displacement by time to find the horizontal velocity. In the example, V = 4 metres per second.
Try a more difficult problem, such as V = -5 metres / 4 seconds. In this problem, V = -1.25. A negative horizontal velocity would mean that the object went backward from its original position.