Law Of Motion - Study Mode

Explanation

Solution: The correct answer is (C) class-III lever . First, what is a lever? A lever is a simple machine that amplifies an applied force. There are three classes of levers, distinguished by the relative positions of the fulcrum (pivot point) , the load (resistance) , and the effort (force applied) . * Class-I Lever: The fulcrum is between the load and the effort. Think of a seesaw. * Class-II Lever: The load is between the fulcrum and the effort. Think of a wheelbarrow. * Class-III Lever: The effort is between the fulcrum and the load. Think of your arm when lifting something or tongs . Now, think about a ladder being used. The fulcrum is the bottom of the ladder resting on the ground. The load is at the top of the ladder where someone is working (or where it rests against a wall). The effort is where you are applying the force to climb the ladder, which is between the bottom (fulcrum) and the top (load). Since the effort is between the fulcrum and the load, a ladder acts as a class-III lever . An inclined plane (Option D) is also a simple machine, but a ladder's primary function involves lever action when climbing.