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Q.3 A well is dug out whose radius is 4.2m and depth is 38m. The earth taken out from well is spread all over a rectangular field whose dimensions are 130m * 115m . Find the rise in the level of field. |
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Answer» ong>GIVEN :-
TO FIND :-
TO KNOW :- ★ Volume of Cuboid = πr²h ★ Volume of Cuboid = L × b × h SOLUTION :- For well ,
Well is in the form of Cylinder. Volume of well dugged out = πr²H ㅤㅤㅤㅤㅤㅤㅤㅤ= (22/7) × (4.2)² × 38 ㅤㅤㅤㅤㅤㅤㅤㅤ= (22/7) × 17.64 × 38 ㅤㅤㅤㅤㅤㅤㅤㅤ= 14747/7 ㅤㅤㅤㅤㅤㅤㅤㅤ= 2106.7 m³ -----(1) __________________________ For field ,
Field is in the form of Cuboid. Volume of field = l × b × h ㅤㅤㅤㅤㅤ ㅤㅤ= 130 × 115 × h ㅤㅤㅤㅤㅤㅤ ㅤ= 14950h m³ -------(2) ♦ When same amount of earth is digged out and spread all over the field , total volume in both the cases will be same. So, equating (1) and (2) , → 2106.7 = 14950h → h = 2106.7/14950 → h = 0.14m = 14cm Hence , there is a rise of 14cm or 0.14m in the field. MORE TO KNOW :- ★ Volume of Cone = (1/3)πr²h ★ Volume of CUBE = edge³ ★ Volume of Sphere = (4/3)πr³ ★ Volume of Hemisphere = (2/3)πr³ |
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