Question

Question 11

Water level in a well was 20 m below ground level. During the rainy season, rainwater collected in different water tanks was drained into the well and the water level rises 5 m above the previous level. The wall of the well is 1 m 20 cm high and a pulley is fixed at a height of 80 cm. Raghu wants to draw water from the well. The minimum length of the rope, that he can use is


(a) 17 m
(b) 18 m
(c) 96 m
(d) 97 m

Answer 1

Details given in the question can be described in the figure shown below

From the above figure, it is clear that,
Minimum length of the rope required to draw the water during the rainy season = Distance between pulley and wall of well + Height of wall of well + Distance between water level during rainy season and ground level
= 80 cm + 1 m 20 cm + 15 m
= (0.8 + 1.2 + 15) m $[\because 1cm=\frac{1}{100}m\Rightarrow 80cm=\frac{80}{100}m=0.80mand1m20cm=1.20m]$
= 17 m