Step-by-step explanation:
The mechanical advantage of a machine is the ratio of the load (the resistance overcome by a machine) to the effort (the force applied). There is no unit for mechanical advantages since the unit for both input and output forces cancel out.
Velocity ratio of simple machine is the ratio of distance travelled by the effort to the distance travelled by theload in the machine. As velocity ratio or ideal mechanical advantage is a simple ratio of two distances, it also does not have the unit. The friction is not involved in it.