Design a Rapid Sand filter for a population of 1, 00,000 with water supply of 220 lit/head/day. Also design under drainage system and wash water troughs Assume data if necessary.
Answers
Answer:
Solution:
Year
Population: (thousands)
Increment per Decade
Incremental Increase
Percentage Increment per Decade
1901
60
-
-
-
1911
65
+5
-
(5+60) x100=+8.33
1921
63
-2
-3
(2+65) x100=-3.07
1931
72
+9
+7
(9+63) x100=+14.28
1941
79
+7
-2
(7+72) x100=+9.72
1951
89
+10
+3
(10+79) x100=+12.66
1961
97
+8
-2
(8+89) x100=8.98
1971
120
+23
+15
(23+97) x100=+23.71
Net values
1
+60
+18
+74.61
Averages
-
8.57
3.0
10.66
+=increase; - = decrease
Arithmetical Progression Method:
Pn = P + ni
Average increases per decade = i = 8.57
Population for the years,
1981= population 1971 + ni, here n=1 decade
= 120 + 8.57 = 128.57
1991= population 1971 + ni, here n=2 decade
= 120 + 2 x 8.57 = 137.14
2001= population 1971 + ni, here n=3 decade
= 120 + 3 x 8.57 = 145.71
1994= population 1991 + (population 2001 - 1991) x 3/10
= 137.14 + (8.57) x 3/10 = 139.71