Final answer:
The mechanical advantage of a simple machine is the ratio of the output force to the input force, the velocity ratio is the ratio of the distance moved by the effort force to the distance moved by the load, and the efficiency is the ratio of output work to input work multiplied by 100.
Step-by-step explanation:
The mechanical advantage of a simple machine is the ratio of the output force to the input force. It determines how much a simple machine amplifies or increases the force applied. Friction can have a significant effect on the mechanical advantage of a simple machine, as it can reduce the efficiency of the machine.
The velocity ratio of a simple machine is the ratio of the distance moved by the effort force to the distance moved by the load. It shows how much the effort force is amplified in terms of distance.
The efficiency of a simple machine is the ratio of output work to input work, multiplied by 100. It represents how well a machine converts input work to useful output work. Friction plays a role in reducing the efficiency of a machine, as some of the input work is converted into heat energy.
None of the terms mentioned above specifically define a simple machine. They are related concepts that describe different aspects of simple machines.