Velocity ratio is the comparison between the amount of force an object creates and the force around it that acts against the object. Velocity ratio is calculated by dividing the force working against the object with the force exerted by the object.
Velocity ratio is also defined as the ratio of a distance through which any part of a machine moves, to that which the driving part moves during the same time. An object has a mechanical advantage if it exerts a force higher than the velocity ratio. This happens because the object’s force is enough to trade off the force against it. When driving a car, for example, the force of gravity and friction are against the car’s motion.