Question

Using a crowbar, a person can remove a nail by exerting little force, whereas pulling directly on the nail requires a large force to remove it (you probably can't). why?

Answer 1

Using a crowbar to remove a nail requires less force because it uses leverage to amplify the input force and increase the mechanical advantage.

Step-by-step explanation:

When using a crowbar to remove a nail, you are using a lever with a large mechanical advantage. The input force you apply to the crowbar is much smaller than the force exerted by the crowbar on the nail. This is because the length of the crowbar provides a greater lever arm, which increases the mechanical advantage.

On the other hand, when you try to pull directly on the nail, you don't have the same leverage as the crowbar, so you need to exert a larger force to overcome the resistance of the nail.

In summary, the crowbar allows you to remove a nail with less force because it uses leverage to amplify the input force and increase the mechanical advantage.

Answer 2

Here we deal with a lever law. It states that product of force and distance from a fixed point on a lever is equal on both sides.

F₁*d₁ = F₂*d₂

By analysing this formula we can see that applying small force on a great length equals great force on a small length.
To remove nail we need to apply certain force. If we use F₁ for this required force we can see that on other side we need to apply certain force. If we have greater arm length we need smaller force. In a crowbar arm length along which we apply force is greater than length of our arm. This leads to a conclusion that we need smaller force when using crowbar. Depending on the length of a nail it is possible that we need to apply force that is greater than force required to remove nail.