What makes the first class lever second class lever third class lever different?
1st order levers have the fulcrum between the load and effort arms. The mechanical advantage of these levers can be greater or less than 1, depending on the length of the arms.2nd order levers have the load portion between the effort portion and the fulcrum. These always have a mechanical advantage greater than 1. They increase the force exerted at the expense of distance.3rd order levers have the effort portion between the load portion and the fulcrum. These always have a mechanical advantage less than 1. They decrease the force exerted with a gain to the distance.