A liquid has a specific weight of 200 lbf/ft3.
The correct answer and explanation is :
The specific weight of a liquid refers to its weight per unit volume and is a measure of the force of gravity acting on a given volume of that liquid. It is typically expressed in units of pounds-force per cubic foot (lbf/ft³) in the Imperial system. In this case, you are given a liquid with a specific weight of 200 lbf/ft³. This means that for every cubic foot of this liquid, its weight is 200 pounds-force.
To clarify:
- Specific weight is different from density, although they are related. The relationship between them is as follows: [
\gamma = \rho \cdot g
] Where: - (\gamma) is the specific weight (in lbf/ft³).
- (\rho) is the density of the liquid (in lbm/ft³).
- (g) is the acceleration due to gravity (in ft/s²). In the Imperial system, the specific weight is typically expressed in lbf/ft³, and it is related to the liquid’s density and the standard acceleration due to gravity (approximately 32.2 ft/s²). The density (in lbm/ft³) is a measure of mass per unit volume, whereas specific weight accounts for the force due to gravity acting on that mass.
Example Calculation (Using Water for Reference):
For example, the specific weight of water at standard conditions is typically about 62.4 lbf/ft³. In contrast, a liquid with a specific weight of 200 lbf/ft³ is significantly denser, meaning it would be much heavier per unit volume than water. This indicates that the liquid is likely denser or heavier than most common fluids like water, oil, or other light liquids.
Importance of Specific Weight:
The specific weight is crucial in many engineering applications, such as fluid mechanics, hydrostatics, and civil engineering, where the weight of fluids influences the design of structures like dams, tanks, and pipes. It also plays a role in calculations related to buoyancy, flow rates, and pressure variations in fluids.
Understanding the specific weight of a liquid allows engineers to predict the behavior of the fluid in various systems and ensures safe and efficient design practices for handling liquids under different conditions.