If Q is the water requirement in L/min and P is population in thousands, what is Buston’s formula to determine fire demand ?
- AQ = 5663 √PCorrect
- BQ = 3182 √P
- CQ = 4637 (1 − 0·01 √P)
- DQ = 100 √P
Solution
Concept
Empirical formulae for fire demand
Formula
Buston: Q = 5663 √P; Kuichling: Q = 3182 √P; NBFU: Q = 4637 √P (1 − 0.01√P)
Step-by-step solution
1. Buston's formula: Q = 5663√P (L/min, P in thousands). 2. Kuichling's formula: 3182√P. 3. National Board of Fire Underwriters: 4637√P(1 − 0.01√P).
Explanation
Different formulae are used for fire demand; Buston's has the largest constant.
Why the other options are wrong
3182√P is Kuichling's formula and 4637(1 − 0.01√P) is the NBFU formula.
Shortcut
Buston 5663; Kuichling 3182; NBFU 4637.
Common mistake
Choosing Kuichling's.
Correct answer: A) Q = 5663 √P