Question

Imagine a huge boulder in the road and a man who wants to move it aside. He pushes it with all his strength, but the boulder won't move. Next, the man tries to move the boulder using a lever, which is a simple machine. Now he's able to move it! But why?

Answer 1

A lever allows the man to move a heavy boulder by using the principle of mechanical advantage, which multiplies the applied force, making it easier to lift or move a heavy object with less effort.

Step-by-step explanation:

The reason the man is able to move the boulder with a lever when he can't by pushing it with his strength alone is due to the principle of mechanical advantage (MA) offered by simple machines like the lever. A lever amplifies an applied force to move a heavier load than one could manage with direct force. The lever works by having a fulcrum, or pivot point, with the effort force applied on one end and the load on the other. When the man applies force to the effort arm of the lever, that effort is magnified through the mechanical advantage of the lever, making it easier to lift or move a heavy object like the boulder

To understand this further, in physics terms, the mechanical advantage of a lever is the ratio of the length of the effort arm to the resistance arm. If the effort arm is longer than the resistance arm, the force applied is amplified and the resistance force necessary to move the load is reduced. This is why despite the boulder's large mass, the man can move it using a simple machine such as a lever, which requires less effort force from him to achieve the same work.