Question

The water pressure developed by 25 meters of water head is about:

• A. 1.5 kg/cm\(^2\)
• B. 2 kg/cm\(^2\)
• C. 2.5 kg/cm\(^2\)
• D. 4 kg/cm\(^2\)

Hint:

The conversion "10 m of water \(\approx\) 1 bar \(\approx\) 1 atm \(\approx\) 1 kgf/cm\(^2\) \(\approx\) 100 kPa" is extremely useful for quick pressure estimations in water-related problems.

Answer 1

The Correct Option is C

Step 1: State the formula for hydrostatic pressure. Pressure \(P\) is given by \( P = \rho g h \), where \(\rho\) is the fluid density, \(g\) is gravity, and \(h\) is the fluid height (head).
Step 2: Use a standard conversion for water head to pressure.
In metric units, a 10-meter column of water exerts a pressure of approximately 1 kgf/cm\(^2\) (or 1 atmosphere). This is a very useful rule of thumb in hydraulic engineering. \[ 10 \text{ m water head} \approx 1 \text{ kgf/cm}^2 \] Step 3: Apply this conversion to the given head. Given water head \(h = 25\) meters. \[ \text{Pressure} = \frac{25 \text{ m}}{10 \text{ m per kgf/cm}^2} = 2.5 \text{ kgf/cm}^2 \] The pressure developed is about 2.5 kg/cm\(^2\).