If you were to attempt to lift a weight with a stick, using a rock as a fulcrum.?

Question

Where would the stick most likely break?

The rock is closer to the weight being lifted. would it break at the fulcrum or in the middle of the stick- the longer half.

Answer 1

it would break on the longer end

Answer 2

Let's start with a stick that has the fulcrum exactly in the middle of the stick. To lift a weight of 10 pounds would require a downward force of 10 pounds on the end of the stick since this isn't a lever; it is a balance. Since 10 pounds of force are pushing down on each end, the stick will break at the fulcrum. Now let's turn this balance into a lever and place the fulcrum closer to the weight. Since we have to force the end of the stick for a longer distance than the distance the weight will move, the amount of work is the same but the force is less than in our previous example (the principle of a lever). Since less force is being applied on the longer end of the stick while the same force is being applied under the weight, the stick will break at the fulcrum. The same reasoning applies with a shovel. The handle will break near the shovel end (stuck in the ground) and not halfway up the handle.

Answer 3

Practically, it would break where the molecular links are the weakest and the external forces exceed them. Theoretically, if we assume the stick is uniform, it will break at the point where it is being subjected to the maximum strain, i.e., where it is "bending" the most. In this case, it will break somewhere at the fulcrum. Imagine the situation with a really elastic stick: it'll be a curve pointing upwards, the maxima being the fulcrum. So the maximum strain is on the most bent part, which is the part above the rock. Get it??

Answer 4

It would break at the fulcrum where the bending moment , and therefore the highest stress, is a maximum.

Answer 5

At the fulcrum.