Define the following terms: 1.1 Resultant force 1.2 Elastic limit 1.3 Strain 1.4 Hydrostatic pressure 1.5 Second moment of area

Here are the definitions for the terms:

1.1 Resultant force
The resultant force is the single force that represents the vector sum of all forces acting on an object. It has the same effect on the object's motion as all the individual forces combined.

1.2 Elastic limit
The elastic limit is the maximum stress a material can withstand without undergoing permanent deformation. If the stress exceeds this limit, the material will not return to its original shape once the load is removed.

1.3 Strain
Strain ($\epsilon$) is a measure of the deformation of a material, defined as the ratio of the change in dimension to the original dimension. It is a dimensionless quantity, often expressed as a percentage or in units like meters per meter.

$$\epsilon = \frac{\Delta L}{L_0}$$

1.4 Hydrostatic pressure
Hydrostatic pressure is the pressure exerted by a fluid at rest due to the force of gravity. It increases with depth and is given by the formula $P = \rho gh$, where $\rho$ is the fluid density, $g$ is the acceleration due to gravity, and $h$ is the depth.

1.5 Second moment of area
The second moment of area, also known as the moment of inertia of an area, is a geometrical property of a cross-section that describes how its area is distributed with respect to an axis. It is used in beam theory to determine a beam's resistance to bending and deflection.