Through these experiments, you concluded that:

1. In a first and second-class lever, as the length of the effort arm or load arm is changed, the distance over which the effort must be applied or the load must be lifted changes. Because the distance over which these forces are applied changes, the effort force also changes.

2. Changing the position of the fulcrum, effort, and load in relation to one another changes the distance over which a load is lifted and effort is applied. The result is a change in the effort force depending upon the lengths of the effort and load arms and position of the fulcrum, load, and effort. When the fulcrum is between the load and effort, the effort force may equal the load force if the load and effort arms are equal. The effort force may be greater than the load force if the effort arm is shorter than the load arm. The effort force may be less than the load force if the effort arm is longer than the load arm. As the fulcrum moves closer to the load, the effort arm becomes longer and the load arm shorter, and the effort force decreases below that of the load force. At some point, the fulcrum may move past the load, and the “first-class lever” is now classified as a “second-class lever.”

3. Mechanical advantage is equal to 1 when the load and effort force are equal and the length of the load arm and effort arm are equal. As the effort force decreases below that of the load force, the mechanical advantage becomes greater than 1. As the effort force increases above that of the load force, the mechanical advantage becomes less than 1. As the effort arm becomes longer than the load arm, the mechanical advantage becomes greater than 1. As the effort arm becomes shorter than the load arm, the mechanical advantage becomes less than 1.