Final answer:
The correct answer is c. The Lever bar, and it is part of the crowbar family. A pry bar is a type of lever, and the mechanical advantage of a lever is the ratio of the effort arm length to the resistance arm length. Levers like pry bars, wheelbarrows, and shovels work on the same principle of exerting force around a pivot point.
Step-by-step explanation:
In the crowbar family, which includes tools that apply the mechanical principle of levers, the pry bar is one version and the correct answer to the student's question is c. The Lever bar. Levers are simple machines that consist of a rigid beam and a fulcrum, or pivot point, which leverage force to move an object. The mechanical advantage (MA) of a lever is defined as the ratio of the length of the effort arm to the length of the resistance arm. Understanding this concept is crucial when comparing different types of levers like a pry bar, wheelbarrow, and shovel. For example, a baseball bat is also a type of lever. Unlike a pry bar, where usually a smaller effort force is applied over a short distance to move a heavier resistance over a smaller distance, in a baseball bat the effort force is smaller and is applied over a larger distance to accelerate the ball which has a smaller resistance force over a long distance.