Which type of force tends to change the shape of an object from a square to a parallelogram?

The correct choice is associated with shear force, which is defined as a force that causes one part of a material to slide past another in a direction parallel to the force. When shear forces are applied to an object, they can distort its shape. This is particularly illustrated by the example of transforming a square into a parallelogram.

In this scenario, the application of shear force results in the layers of material shifting relative to each other, leading to an angular distortion while retaining their overall area. This change from a square to a parallelogram visually represents how shear stress affects the internal structure of materials—creating a slant and changing the angle between adjacent sides without altering their lengths.

Understanding shear force is critical in structural collapse scenarios, as it helps in assessing how and why buildings might fail under certain loads, especially in cases of lateral forces during events like earthquakes or significant wind.