Final answer:
Second-class levers have a mechanical advantage greater than one because the input arm is longer than the output arm.
Step-by-step explanation:
A second-class lever is a type of lever where the load is positioned between the fulcrum and the effort force. In these levers, the input arm is longer than the output arm. The mechanical advantage (MA) of a lever is determined by the ratio of the lengths of the input arm and the output arm. Since the input arm is longer, the MA of a second-class lever is always greater than one, which means it provides a mechanical advantage.