Acceleration due to gravity, g = 9.81 m/s
unless otherwise specified Density of water = 1,000 kg/m
The Correct Answer and Explanation is:
Correct Information:
- Acceleration due to gravity, g = 9.81 m/s²
- Density of water = 1,000 kg/m³
Explanation
The acceleration due to gravity, often represented by the symbol g, is the rate at which an object speeds up as it falls freely toward the Earth. On the surface of Earth, this value is approximately 9.81 meters per second squared (m/s²). This means that every second, the velocity of a freely falling object increases by 9.81 meters per second, assuming no air resistance.
Gravity is a force that pulls objects toward the center of the Earth. The acceleration caused by this force is the same for all objects regardless of their mass. For example, if you dropped a feather and a stone in a vacuum where there is no air resistance, they would hit the ground at the same time because both accelerate at 9.81 m/s².
Now let’s consider the density of water, which is given as 1,000 kilograms per cubic meter (kg/m³). This is the mass of one cubic meter of pure water. Density is calculated using the formula:
Density (ρ) = Mass / Volume
Water’s density is often used as a reference point for comparing other substances. For example, if an object has a density greater than 1,000 kg/m³, it will sink in water; if it has a lower density, it will float.
These two constants — gravitational acceleration and water density — are commonly used in physics and engineering calculations. For instance, in fluid mechanics, the pressure at a certain depth in water is calculated using the formula:
Pressure = ρ × g × h
Here, ρ is the density of the fluid (water), g is gravitational acceleration, and h is the depth. Understanding both g and water’s density helps in solving many real-world problems such as designing dams, calculating buoyancy, and estimating hydrostatic pressure.
