Final answer:
Shear force at a cross-section of a beam is defined as the algebraic sum of transverse forces on one side of the section. It is crucial to understand how materials respond to external loads, resulting in a shear deformation, related to the material's shear modulus and the applied forces. Thus, the option "1" is the correct answer.
Step-by-step explanation:
The definition of shear force at a cross-section of a beam or other member subject to bending is the algebraic sum of transverse forces on one side of the section. This means that when calculating the shear force, we only consider the transverse forces (perpendicular to the length of the beam) and we sum them up, taking directions into account, on either the left or right side of the section in question.
Shear force is a critical factor in structural engineering as it influences how materials will respond to external loads. It can induce a deformation in the material characterized by a shift in layers, which is directly related to shear stress and shear modulus. The shear modulus is a measure of a material's ability to resist shear deformation and is dependent on the material's inherent properties as well as the cross-sectional area and the applied forces.
Shear deformation is a result of shear stress and is described by the shift of layers, which can be mathematically expressed relative to the transverse distance and the magnitude of the applied force. The properties of the material, including the shear modulus, play a significant role in determining the extent of deformation under shear force.