Final answer:
Interface metrics are used to assess the complexity of a module's input and output relationships with external devices. An external force is defined as a force generated outside the system of interest that acts on an object inside the system.
Step-by-step explanation:
Interface metrics are used to assess the complexity of a module's input and output relationships with external devices. These metrics measure the number of inputs and outputs, as well as the complexity of the data exchanged.
An external force is defined as a force generated outside the system of interest that acts on an object inside the system. Therefore, the statement 'An external force is defined as a force generated outside the system of interest that acts on an object inside the system' is True.